Same here.

I don't know why I'm also like this but I've been red pilled about shit so hard I know how shitty everything is and I'm also a fat unhealthy slob who can't run away or hide. And my country has liberal self defense laws so it doesn't help me feel any more safe than before.

Practive and experience will help, but you have to start somewhere.

Been there.
If you're insecure about yourself, do martial arts (or box) dude! It grants you confidence, endurance, serenity & being in a good shape. You'll be respected.
Improve your body-language.
And if you feel less competent than others intellectually, read about the field you're longing to work at, talk to experts, don't leave any unanswered questions!

you guys think xanax can help with this?

Adopt stoicism. I mean the actual philosophy, it really works.

Source: Me. I had social phobia to a degree where it was basically indistinguishable from agoraphobia. I didn't leave the house anymore because of fear. Then I started to change my outlook.