I just quit my teaching job under very similar circumstances. I was also a “complainer” and quite vocal about the things I didn’t agree with. The place was a mess, and was giving me anxiety. I was/am in the union and our rep gave some great guidance but it became a lost cause for me because it’s really just stopped being worth the fight against unresponsive admin.

Tip: understand your contract. READ THAT SHIT. and if admin try to manipulate you into going above and beyond the demands of your contract tell admin to shove it for as long as you can. Work your duty day and don’t give them your lunch. Take what is rightfully yours. I’m starting at another school in another county in two weeks.