The insidious thing about burnout is you can’t think clearly when you’re burned out. I’ve been heavily burned out twice and I can relate to just wanting to work in a bar or something but after a couple weeks off you’ll be able to think clearly again. Worst case it’s 2 weeks of paid leave before you quit, best case you come back grateful for the opportunity and recharged.
Your team lead sounds like a pain in the ass, the founders would probably get rid of them instead of you if you gave them an ultimatum but my advice would be to take time out before you do anything rash.
Good luck!