Greetings!

I am rather sure of that I have some sort of bipolar disorder (I guess type II is most fitting) but haven't received a legal diagnosis (or what to call it), and I'm wondering if it is "worth it"? What is your experience with receiving a diagnosis?
I don't think I am in need of any medication, do you think there's reason to get help if you're not interested in being medicated?

I'll give some personal backstory to the question;
I've been more or less low during most of my life, age 9 being marking the point where I have my earliest memories from it. My father has always been more or less depressed, and always took out it aggressively on his family (which most likely was the source of my low mood in my younger years). Age 10-12 is rather blurry, but I remember anxiety being an increasing problem for me and I had my first panic attack at age 13, as well as testing out self-harm. At age 15 I was severly depressed, life had no meaning and I spent most time just sleeping/lying in my bed in the dark. I lost a lot of weight and had several panic attacs every day and night, as well as resorted to self-harm for coping. This went on during october-april. I got better, and the summer that followed I was in a constant euphoric mood. I was invincible and had never experienced anything like it. I spent most of my days running around barefoot until the sunset, just doing lots and lots of stuff and being really eager for the future. It was amazing. School eventually begun again, things went back to normal. I was a bit down during the winter, but I can't remember it being extreme. Winter at age 17 I became severly depressed again, although this time I was in a relationship and not able to hide in the dark all day. I hid my emotional state at all cost, my partner was depressed as well, and I needed to "hold them up", and as we both started to feel better we broke up (this was in march). Things went better and I started to feel alive again (relieved from the burden of a relationship), spring was coming and everything was going great. And greater. And even greater. And eventually, not so great... I started projects, cut my hair every other week and dyed it... my thoughts were racing, I came up with all these grand ideas and my friends started to get annoyed at me, telling me I had changed. I got mad at them becuase they couldn't keep up with me, and eventually I couldn't either. It was as if my body moved in slow motion compared to my mind, and I was really scared. I moved away from home, stopped eating and sleeping. I exercised to the extreme as well, and eventually started experiencing depersonalisation and derealisation. By pure luck I didn't harm myself severly I won't do that again. I eventually hit a wall, experienced some of the worst anxiety attacks I ever had, moved back home and recovered. Met a new partner at age 18 and got rather low again during winter (started to self-harm again, but hid it as well). Got a bit better after winter I guess, but then worse again at 19. I graduated at spring and things started to go downhill at august. I moved away from home again, but this time it just got worse, and it didn't get better as I moved back home (a lot of ****** things that made things worse happened as well). I started self-harming more seriously and couldn't keep away the intrusive thoughts that made me do it, but this time my partner found out and made me go into therapy. January came, and I suddenly started to feel a lot better... then even better, and yeah, I recognized the pattern it didn't spin out of proportion as bad as last time, but I experienced a lot of racing thoughts... I did some bad impulsive things, excercised excessively, spent lots of money on crap, and was extremely irritable/agressive (I won't hurt a fly normally) and felt extreme guilt for acting in a way that was so unlike my normal self. Around the same time I came in touch with someone online who had just been diagnosed with cyclothymia, I could really relate to their story and talked to my therapist about it (very exitedly :P I was extremely hypomanic at that point) and they recommended me to talk to a psychologist to receive a possible diagnosis. Although when I called to get in touch with the psychologist, the lady at the desk snarkily replied "Well, if you aren't depressed right now, there's no reason for you to call us". I was really put off by this, but eventually got a time. I got to talk to the psychologist during 3 sessions, fill out some paperwork and etc, and in the end he told me "We're suspecting that you might very well be suffering from a bipolar disorder. Do you feel you need any help?" to which I of course said no, I was hypomanic and doing peeeerfectly fine. I figured that if I'd hit a wall I'd be able to go back, but at that time it wasn't necessairy.
Slipping out of my hypomanic state I of course experienced a small low, but I have now been experiencing the longest stable period I can remember (I'm 20 at this time, and I've been stable since ~june this year).

TL;DR - I've been experiencing episodes of lower moods every winter for as far as I remember, and these past 6 years I've had a deeper depressive episode with a following an episode of euphoric mood, impulsiveness, irritability & etc every other year.

I have now moved away from home, I am living by myself in a new city.
I don't think I won't be able to take care of myself if anything happens, and I don't think my mood is to change dramatically any time soon, but... in case something could happen, is it good to have received a diagnosis? Would that be of any help? Is it good to deal with it as soon as possible, or do I have to wait for another moodswing to set in to be "believable"? I know when I hit an extreme I have felt it being very helpful to have someone professional to talk to about it but I'm usually reluctant at seeking help because I'm "strong alone" and/or "not worth it".