Sounds like you believed in their "mission". All that is PR. Changing to a startup will be to believe in someone else's "dream" who also will transform into sel

Sounds like you believed in their "mission". All that is PR. Changing to a startup will be to believe in someone else's "dream" who also will transform into selling out or a power struggle. And that will burn you out even more. I'd use some of that money to invest in yourself. Take as much vacation and benefits as you can. Make the moves to achieve FIRE. Pay someone to help you with your side projects or to teach you things, this can be a good exit with open source turning into a startup (perhaps pay someone to find your future clients before you take the jump). Be careful, your FAANG sting probably twisted your view of the world. See Lean Startup.