I will admit that I've been here for several years under several different names, I have been told multiple times that my ex was abusive that I ought to leave him, that I was damaging the kids.
I genuinely believed he could change because he wasn't 'that bad' and sure, I left him once for a year before going back and things were better, he had anger management, we had counselling, things were different and I stuck it out another few years before he started to slip, and then it took me another 2 years to pluck up the courage to finally say 'enough'
Even now, he still keeps asking me to try again, telling me we can fix it... we can't because I dont want to, my life is so much better with out him. We actually get on better as co-parents than as a couple because there isn't that pressure of sex or controlling issues.
Leaving is scary, its daunting, its not what you wanted or what you ever envisioned your life, but its better, my god, is it better.
You can do this, I know you won't until YOU are ready, but plan, get everything straight that you can and go for it. You are strong enough.