The sad thing is that the DC's grow up with this kind of treatment being perceived as the norm, and thus grow up to be 'abusers' or 'abused' on some level.
I am on my own RubyPink... it is hard and scary and sad sometimes, and like your life, mine was messy and complicated. But it's a damn sight easier not feeling like I am a neurotic, paranoid of just wrong.. After 6 mnths of counselling I am getting there.
It is about drawing a line, for yourself, your DC's and finding the courage to take the steps.
I read the threads about seemingly 'normal' relationships, and that put how acceptable what I was going through. Healthy relationships don't leave you writhing in self doubt with low self esteem, they just don't give you cause to think the kind of thoughts you are having.
It's hard to let go and to mourn what must have been a good enough relationship at some point. But the thought of staying for another 25 yrs? Is that what you see lovey?
Because there is nothing to compare to the serenity of having a cup of tea without being on tender hooks that life will come crashing down, or you are trying to be the eternal peacemaker.
Of course I was at some point where you are now, terrified of being trapped, terrified equally of change, lonely as hell but scared of being alone.
I hope life grants you the strength to change things, however it bests suits you, so the rest of your life is in some way how you dream it could be in your day dreams... take care xx