I agree, you're wise to recognize your limits. You're wise to see the pattern here over nine months...always dealing with what he wants, his issues, his desire to change and tweak what you originally agreed to, him doing things behind your back.
You're only nine months in. I don't remember where I read it, but a comment in the last couple months from someone saying when they broke up with a boyfriend, it felt like the end of the world...a year later, it hurt...five years later it was okay...and ten years later she was incredibly grateful to have made that decision.
It may be hard emotionally to contemplate this, but it sounds like you're seeing things clearly. And these things will almost undoubtedly continue. Best to see it now. Good luck.