Well, the first step is awareness.
Sounds like you won't be fooled, which is a good thing. Abuse comes in many forms - this is certainly one of them. I am sure you know this, but you'll have to draw the line somewhere. I was married to a mentally abusive man who quickly turned into a physically abusive one as soon as he noticed I was growing a pair.
I should have left way sooner - I spouted out all of what you are saying now. Yes, people change, but sometimes we have to realize that we cannot wait for it to happen.
I guess I am just writing to say, that I wish you strength. Know that you are not alone, and that if you leave this is not a failure.