Being deceived and having hope doesn't make you dumb. You shouldn't engage in the negative self talk.
First step is to disengage from him. Don't ask your abuser to please behave himself this time because he's obviously not going to, he hasn't changed a bit from the first time.
No fighting - this indicates yourre oopen to further manipulation. No engagement, this indicates you're on unsound footing and looking for reassurance from him, which you know is already a poisoned well. You can listen to what he has to say, but don't engage in questions or answers.
Begin the process of cutting him out of your life. If he's cheating, that's what needs to happen anyway. If he's not, you can always reverse the process. But it's important that you get to a place where you know you'll be okay without him. That's the "worst case" scenario (even if you determine that's exactly what needs to happen), and if it goes better than what you're anticipating, you'll be okay then, too.
Once you have some space, you can plan more clearly about gaining financial independence and whatever else you need to, logistically. Every problem has solutions that are small, really managed steps. None of those steps are outside your ability. The only thing that can overwhelm you is trying to solve the whole big problem in one go.
Disengage, start the process of writing him off, start the process of grieving your lost relationship, and start planning.
