What's the roadmap to recovery from social anxiety?

I've had social anxiety for as long as I can remember. I have been trying to push it's boundaries with my own kind of exposure therapy by taking myself out of the comfort zone but the kicker is that it has been not super successful.

I'm very rejection sensitive, autistic, and have traits of BPD from a history of being bullied which causes me to feel extreme internal pain when it comes to new social situations. 20 percent of what I think about is embarrassing memories so I get to relive that even when I'm not in scary situations.

I work as a grocery clerk. My previous job I was constantly doing vacation home rental presentations. I can put up a good facade but my internal experience has constantly been that of pain. It's pretty discouraging when I didn't improve much at all from that despite doing it over and over for years.

The worst thing is self expression. I dread any of it, doing it feels like a death sentence. And I've come under criticism for it in return for exposing myself and it makes social anxiety feel like a valid anxiety to have compared to other anxieties. Because I do genuinely get criticized and it hurts so bad and leaves such a wound that it makes me feel like I should never again try.

I can't practice social skills either when there's this barrier.

Any advice?