Hi, I would like to ask you about the validity of my diagnoses (I know, it's pretty hard to do over the internet) and ask for help with understanding some related psychiatric nomenclature. Sorry for poor english, I'm not a native speaker.
So over the last 11 years of my life (I'm a 25 yo male) I've been diagnosed with both depression and SPD/SzPD (schizoid/schizotypal personality disorder) with traits of APD (avoidant) by about 5 different psychiatrists. Recently I was diagnosed with schizophrenia.
At about 12 yo my problems began suddenly, I had been a happy and social child before; a "very gifted child", at top of my class, etc.. Maybe I could have been a little eccentric when it came to interacting with other people, but it definitely didn't stop me from making really close friends and being "socially active" and likeable.


God-fearing phase

At 12-14 yo I had a really hard time/ feeling guilty about accepting my sexuality/ sexual needs (I'm straight though).
At that time there was also this weird period, when I thought that I suddenly began understanding secret messages in Bible (I hadn't been intereseted in God, church etc. earlier, but my parents made me to go to church every Sunday; they are Christians). Almost every sentence was somehow connected with my situation (not personally with me though, that would be "too crazy") and with condemning sexuality. I was suddenly extremely interested in going to church and tryng to be "a good Christian". Tried months-lasting "no-fap" to "finally go back to the state of child-like purity and not to feel sexual urges anymore" (I know, I was really ignorant about how sexuality works; but the only "true" info about it came from priests, I didn't trust other sources when it came to sexuality). This lasted for 1-2 years.
This is the time when my problems began. Suddenly I started being apathetic, more aloof, lethargic, anxious, life began being a chore, suicidal ideations. When it came to social life I stuck with a few of my mates from elementary school and we would meet every week or so, but I was different. Lower in our small "social hierarchy", surpressing/not accepting my anger, more eccentric, missing some social cues. I forced myself to have this regular contact with my peers because it felt healthier than isolation. I didn't participate in drinking/smoking weed though, and was really awkward at parties. I didn't make any new friends in middle school as well.
I had my first meting with a psychiatrist and was diagnosed with depression and anxiety. They suspected that it was age-realted and will resolve with time. They put me on SSRIs. When this didn't work that well, they tried Olanzapine and Risperidone too for some reason, but it made me too tired/zombified. Since then I stayed on Sertraline.
Then (14-15yo) I suddenly decided that all of this church going/Bible reading was just a shallow way not to feel guilty about my sexuality. I was like "**** that BS, I don't even belive in God, it's all about my anxiety about my sexuality, that's what forces me to be "a good Christian" in a really shallow sense". "That's probably why my life sucks so much. Let's party and embrace my sexuality instead and see what happens." was my thinking now.

"Party", drugs and maths phase

So now, about 15 yo I started drinking with my friends and partying every week or so. I tried hanging out with people from different schools to have more social interactions. It was all pretty lame though. I was accepted, but not like in my childhood. I was anxious and somewhat awkward/eccentric at times; I thought peers didn't like/respect me enough. I felt like a loser all the time. I didn't really enjoy the human contact that much, although it was more exciting than being alone.
For the first time I had a couple one-night stands with pretty attractive girls, but it wasn't really enjoyable (I've heard I'm pretty attractive, and I didn't really have to initiate those interactions; I was too shy to talk to women anyway; I had little to no "game" which also made me feel like a loser). I lacked the ability to have a long-term romantic relationship (I didn't even try). I felt like I was too weird/broken and needed to focus on improving myself first.
I started hating my face. I became obsessive and extreme about it. I have a slight overbite that I thought was the cause of my social failures. I tried jutting my mandible forward all the time (even when nobody was looking) to make it into an unconcious habit. At that time I've read some lookism/redpill stuff, not too much, but enough to fuel my obsession with my looks and hatred towards people. My thoughts were "It's so unfair that people treat you differently depending on how you look. What if I was deformed? F.i. would my mother pay less attention to me during childhood? What if I actually am deformed (the overbite thing)? Let's obssesively take photos of myself from different angles for 1-2 hours to determine my worth to society on a 1-10 scale". All of this made me even more anxious and bitter. Elliot Rodger kind of thoughts came to my mind, but I wouldn't ever act on them.
At the same time I tried to "live my life to the fullest" so I started using weed with my friends (I was 17 yo by then). I liked the way it took my anxiety away. Enjoying weed by myself was best for my anxiety. Slowly I became really reclusive, valuing my "independence" over excitement of human contact.
I started being obsessed with math. I was always really good at math, but I never worked hard at it. Now I would spend my whole days solving USAMO-like problems. I went to the best math-oriented class in the best math-oriented high school in my country. One year I even scored 1st in my country in a math olympiad (analogue of USAMO in my country; the problems are generally even harder then USAMO in my opinion). The problem was I was avoiding facing my problems by sinking into math. It wasn't a healthy, productive learning rutine. Instead it was obsessive and impoverishing me as a person. I was mono-maniacal and underdeveloped in all the other areas of life. I really enjoyed the „prestige” of being really good at something, I guess I can be pretty competitive when I see I have a chance of winning. I did really badly in all the other classes.
When my parents caught me smoking weed they sent me to my first therapy. It lasted for 1,5-2 years. I was given a MMPI test and was diagnosed with mixed features of Schizoid-Avoidant-Asocial personality disorder. I went to a new psychiatrist and was prescribed Venlafaxine and Agomelatine in high doses. He diagnosed me as mostly Avoidant and depressed.


Last couple of years

After about a year of regular use, the weed started making me more anxious, so I switched to codeine (it's OTC in my country). It turned out to be a perfect drug: slight euphoria, no anxiety, no need for an unreliable drug dealer (I really valued this independence/ lack of social BS), I could be high without my parents ever knowing. I quickly became addicted to codeine for 1,5 years. Then I switched my theraphy for a more addiction-focused one. This second theraphy lasted for 9 months.
After the addiction-focused therapy I managed to stay sober for 4 years and study math in university. At that time (so for 4 years) I went to a third, free theraphy (my country/insurance payed for it), which didn't really help me much. Looking back it was probably pretty ******, but I didn't actively try seraching for a different one. I thought I was the main problem.
The problems I had at that time were: extreme obsession with my looks, lack of social/romantic life, rare self harm. I've literally made no friends after highschool and cut off all the contacts with people I knew. My life felt like it was passing me by, my best years are being wasted etc. It was a terrible period in my life. I blamed it all mostly on my looks. It motivated me to work out obsessively 5 days/week.
Then (at 23 yo) I made some money and decided to try fixing my overbite with double jaw surgery (since my teeth can't be fixed with simple braces). My family though I was crazy, but I didn't care. I made a year long intense research into different types of jaw surgeries, best surgeons etc. I could spend 2 hours in front of a mirror thinking about what kinds of jaw movements (counter clock-wise? impaction? how many mm of bone movement? etc.) would make me look the best. After the year of research and all kinds of different x-rays and consultations with doctors it turned out I was a really bad candidate for the surgery (poor quality bones).
This was exactly at the end of 2021. This was when I decided to try taking my life, but failed to. So all that happened was that I relapsed and spend the whole year 2022 using opiates again. I've found a „plug” for oxycodone through internet and decided to try it a few times. I overdosed three times (didn't really try to kill myself, but didn't really care about living either) and thus was forced to go to a psychiatric hospital twice (in March and June), spending there a month each time.
There I was put on Abilify 15mg and Quetiapine 200mg which really helped with the obsession with my face. They ruled out schizophrenia and diagnosed me with SPD/SzPD each time. They also weaned me off antidepressants.
Now my new psychiatrist (last 6 months) diagnoses me with schizpohrenia with mainly negative symptoms instead of depression; he said he is not sure about this diagnosis though. I agree with him on some things: what I feel is not depressive sadness, it's mostly apathy, lethargy, emptyness. For the past couple of months I've been really inactive and that's my main problem now. I can spend my whole day laying in bed watching YT or trying to fall asleep, sleeping for 12-14h daily (I'm retaking a year at my university, so I have less classes and I'm able to manage studing while being in this ****** state). I don't feel sad, but I am worring about the future, about failing in life and I am really zombiefied. I don't care about my face or about lack of social/romantic life now.
I've been sober from opiates for the past 2 months, but I've been taking black market methylphenidate (Ritalin, Concerta) to help me with studing for the finals. I couldn't get out of my bed otherwise. Ritalin is not a sustainable solution though, and my psychiatrist refuses to prescribe it to me since i don't have ADHD.
Currently I'm trying to wean myself off Quetiapine, but staying on Abilify. If this doesn't work for my "negative schizophrenic symptoms", then my psychiatrists will probably prescribe me cariprazine.

Now my questions are:
1. What do you think about all the diagnoses I've been given? Is neuroleptic treatment better than antidepressants (which didn't really work for me in any noticable way) in my case?
2. What's the connection between SPD/SzPD and schizophrenia? Some sources say they are completly different things, others say that SPD is on a schizpohrenia-spectrum (whatever this means), so there is some connection. It's really confusing.
Sorry for the long post, but I wanted to give you as much significant info about myself as I could. I know I should probably talk to another psychiatrist about it, but after 5 different ones I'm pretty resigned. Maybe here I will find some answers, or at least some interesting thoughts about what's going on in my case.