I left last year. I hated how bitter I've become but I couldn't help it, I was so disillusioned with this place. My cynicism started affecting my daily life and relationships and I despised myself for it. My life slowly but surely changed for the better when I didn't have to work here anymore. Sad but true.
If you can't leave for whatever reason, then at least don't ever let your workplace negativity overcome your life. It's never worth it in the end.