Yeah. I think a lot of that is coming from having been abused as a kid.

When your parents mistreat you, they tell you over and over again that you're worthless and not good enough and [insert insult here]. Eventually you start to memorize those things and they play back in your mind, even if you consciously know they're not true. It's just that you've been told them so often you're afraid they are true...

So you have to kind of re-teach yourself with more realistic statements. I highly recommend reading up on autism self-advocacy and disability rights in general; there are an awful lot of people out there who are sick and tired of being considered inferior and incapable because they have some diagnosis or other, and they have a lot of useful things to say. When those little recordings in your brain start playing, you can come right back at them and challenge them. Like if you tell yourself you're worthless when you messed up on something, you can correct that to just the fact: That you messed up on something. Or when somebody comes at you with "OMG you're such a poor pitiful tragedy", you can come back at them with "Screw you; I ain't no tragedy." That kind of thing. (Yeah, you can swear at them if you like when they get patronizing like that. It's cathartic.)

You don't have to justify your existence. You don't have to prove your worth. You are, by default, worth quite a lot. After all, you're human; we're quite possibly the most complex structures in the universe, capable of understanding the fact of our own existence and deducing facts about things light-years away just by looking at a ray of light from a star. Humans are valuable just because they're humans.

I don't know if I'll ever win out against those recordings in my own brain, but I'm making progress. Maybe I'll have to challenge them my whole life, but each time it gets easier. It's a matter of perspective, I guess--learning what the world is really like, instead of believing what an abusive parent told you about it.