Hi, and welcome. This is a place where a lot of people can understand what you've gone through because many have had similar experiences. For me, I can sympathize with a lot of your feelings, and learning a few months ago that I am autistic took a lot of the shame away. I had been wondering forever what was wrong with me and why I was "broken," and now I know I am not broken, even though some things are harder, and can explain a lot of why I haven't been able to do what I wanted to or lived up to others' expectations. This took away a lot of the feelings of shame, and now I can identify more clearly why things happened the way they did. This is actually giving me a lot of hope for the future, because I can find help for specific things I need help with, and let me do the things I can do well.
I understand that right now you're feeling very depressed and anxious, and when you are feeling that way it is hard to imagine that it will ever, could ever, get better. But it will. I promise.