So it seems this is largely related to the emotional dysregulation found in ADHD as well as the social problems in autism. If I can learn to manage the former and stop some bad habits in the latter, that should help.
Absolutely! This is a good way to break it down. I think it is very likely that one can reduce the symptoms of rejection sensitivity dysphoria with insight, support, effort, and time.
Sometimes, learning as much as you can about something can help you manage it better. You can begin to understand where your brain is leading you astray in terms of its response to perceived rejection.
https://my.clevelandclinic.org/health/diseases/24099-rejection-sensitive-dysphoria-rsd
https://mindfulcenter.org/what-is-rejection-sensitivity-dysphoria-rsd/
https://neurodivergentinsights.com/blog/how-to-deal-with-rejection-sensitive-dysphoria