Ohh I feel you. I also struggle with having a garbage job, needing it, and letting it ruin my mental state.

The usual advice is to emotionally distance yourself from bad interactions. No idea how to do that though.

What kind of works for me is to offset the bad stuff with the good. Play video games with friends, in person, sitting on a couch, as it should be. Start a side project that nobody needs but you, purely for the sensation of making a thing that you like.

And at the earliest opportunity, get out of there. Corpos are the enemy.