[rkk3]

Getting into YC is an accomplishment, but you clearly don't have a real business yet. To paraphrase a saying... the reason that startup politics is so vicious is because the stakes are so small.

It's painful but in general I'd try to move on and be thankful that you were able to end your journey with that CEO early, after only a year and a half! Life is too short.

Still it's worth the effort to do a few legal consults to know your options. Litigation is one, but it's emotionally draining and could drag on for years. How good was your bookkeeping? Did you have a vesting agreement? Did you sign away your IP? Did you sign any non disparage agreements - you could be sued for damages, especially if those communications are written.