omg: hugs love, just hugs. been there, had that, it's awful. Perhaps tell him clearly today during daylight not to do that again. Then if you are asleep and he tries it, just get up and go sleep in the kids room. it's what i did.
bejeezus: love we all feel like that, the surely it wasn't THAT bad, he didn't mean it, it was the drugs/drink/upbringing whatever. But the fact is that he DID do it, knowingly or not, he did it. He won't ever change, he really won't so the only thing you can do is change, your postcode! 
It's a survival technique borne of the very slow and gradual creep of the abuse, we dismiss it at the beginning, and it becomes a habit.
You are not over-reacting. you know that when you sit yourself down in the cold light of day. It's fear of the un-known working away at you.
Tell yourself this, if you stop this divorce tomorrow, your life will return to how it was. Or you carry on and then your life can change, and YOU get to choose mostly how it changes. I know which one I'd go for... but that's cos I AM out.
You are doing the right thing.