Trouble treating depression/anxiety/social anxiety with autism

I spent the winter in a very severe depression that I've pulled out of enough to make it about a moderate-ish depression I'm still struggling with. I'm having even more trouble than usual pulling apart depression and anxiety from truth, I think largely because of discovering I'm autistic last year shortly before this all.

One way I used to try to push away some depressive thoughts was just telling myself unconditionally good things about myself/life. Basically, telling myself over and over in public for example that no one's feeling dislike toward me and everyone likes me, things like that. Obviously these thoughts aren't totally realistic for anybody, but hammering my mind with them would help somewhat. Things like this were part of what helped me build some more shaky confidence.
But now, between the fact that I have more reason to believe that, to put it really bluntly, I am a type of person a lot of people would just not like, and I could be reading people wrong (probably even more than I'd been aware of before) so might even be wrong about the times I think people do like me, I know they're honestly even more unrealistic for me. So 90% of the time I think someone's thinking something negative or disliking me, I don't know how to dispute it or whether I should, and if anything usually end up encouraging the thoughts.
Usually at the end of extra severe depressive spells, I use this type of stuff to help pull myself up. Instead, right now, it feels like I'm both trying to tear myself down and apart and change myself (somewhat purposely, somewhat not), and build myself up, and it's not exactly working out. I feel like my views of myself and the world are tearing apart and I have so many conflicting views. My mind doesn't even know the meaning of self esteem or a strong stable sense of self right now honestly.

Sometimes at this point I'd try to do self help stuff, but eh. I can't figure out how to make CBT work, or if maybe it just won't, now. For example, if I'm thinking someone's thinking negatively about me, I could try to tell myself that I'm "filtering, mind-reading, jumping to conclusions, and/or using emotional reasoning." But before, these would've all been to try to convince myself that the negative perception is absolutely wrong and that the person wasn't thinking negatively about me. Since realizing I'm autistic I've realized that, I'm sorry, maybe I do have reason to think that people might think negatively about me a little more than average. And yes, in the end, who cares what those people think, but that's not entirely the point. I still want to know the truth, I don't want to lie to myself and give myself an inaccurately positive perception of things. Plus, if there are some changes I need to make in myself to make myself a little more likable, maybe that's just life.
In all of the reading I was doing about autism the past year, the words, "sometimes autistic women tend to think men/people like them more than they actually do," (or something similar) have stuck in my head so much. Rather than working toward being a self-confident person who doesn't care what people think, I'm now terrified to be confident and have basically convinced myself that I'm actually better off if I'm not. At least if I'm not confident, I won't be prone to thinking people like me if they don't and maybe will see things the most accurately; now that I've scared myself, I'd rather risk seeing things pessimistically than too optimistically, but I know that's not healthy.

This all makes me feel even more hopeless about therapists too, because so many do CBT (see above problem), and also because they won't understand the autism thing and the differences and I feel even more like half the things they say won't apply or work for me.

Does anyone else struggle in similar ways? Any advice?

Since my diagnosis, it's kind of worked in the opposite direction to what you've described. Prior to the diagnosis I was (without equating it to being autistic) filtering everything that I said before I said it... which was very tiring... and if I got it wrong (which may or may not have been the case... the other person could have just been having a bad day), I would berate myself to such a degree that depression and anxiety would hit me like a ton of bricks.

Now however, having had some closure with the diagnosis (I'd figured there was something wrong but didn't know what), I feel a bit of security in acknowledging that I'm not always going to get it right... the other person doesn't need to know why... but I do, and I can just learn from the experience.

I feel you a lot. I had my own severe major depression episode in March because my family has stigma against medication for mental illness, and really wanted me off of it, so I listened to them, and three months later, I became severely depressed. Almost hospitalized.

Over my years of therapy, I have found CBT not helpful, nor mindfulness, which is the other technique people have tried with me. Now, when I'm thinking something bad, I do the exact same you do "oh, I'm black-and-white thinking/mind reading/etc.", but that's that. I just kinda tell myself "I know I'm doing that, but I still believe in that fact." I can't seem to get this notion out of my head.

And mindfulness, the point was to think about your surroundings and things going on around you, but if something is on my mind, I can't "shake it off". I just keep thinking the same thing over and over again until it's gone/resolved.

I've been told I may struggle with these things because of ASD, specifically the rigid thinking part of it. I have severe rigid thinking. I will concentrate on one negative thought and it's hard for me to let go of that thought. So I've been suggested to try DBT, but would like to actually do therapy for autism-related issues, as my family didn't see that as a priority for me, so...

I have ASD so please be kind if I say something socially unacceptable. Thank you.