Yes, I'm seeing therapists at the moment. Apparently I'm extremely dissociative.

OK, well your therapist are certainly going to know best how to advise you. I found traditional martial arts helps me deal with stress, but you may not be well enough to embark on that kind of training. The traditional arts have names ending in “do” and include a lot of psychology of conflict.

Disciplines ending” Jitsu“ focus on the physical skills with a little to no philosophical content, and probably would not help you except physical health

Ask your therapist if they think a traditional Martial art would help you. If you’re not ready for it then just reading martial arts philosophy may help for example Bruce Lee was surprisingly insightful as a philosopher and actually major in philosophy in college.

No. I'm still at the unhealthy coping mechanisms phase of therapy. I don't see that change any time soon, because going outside is exhausting and painful and I can't do that a lot.

So even if you don’t do a martial art, you can read philosophy from Bruce Lee or books about aikido philosophy. They are helpful in finding non-destructive ways to deal with conflict and social pressure.