You have provided a lot of detail. Well done for getting through that mess without quitting or being fired. Book 2 weeks off if possible. Relax for 2 weeks.

You have provided a lot of detail. Well done for getting through that mess without quitting or being fired. Book 2 weeks off if possible. Relax for 2 weeks. Then do 9-5 "work to rule", grind leetcode in the evenings for 3-12mths, get a $200k+ job for a proper company.