I've been in this situation before, also with my first startup. Bailing was the one of the best decisions I've ever made and gave me the emotional strength to evaluate who I want to keep in my circle of friends/professional network.

After I left I got a regular job with regular pay to get myself level financially and emotionally. After another year or so of that, I'm at a startup again. This time, with much more success.

I'd cut the cord and get out.