Hi Awkward, first of all well done on having the strength to make the decision to finish things with him!! You clearly know it was the right decision from his past (and this) behavior, but I can see how it might be painful for you in letting him/things go. You will have a lot of history, good memories, high's, low's, hope's, dreams, experiences with him (?) and you have a child with him.
But try not to let all of that cloud your vision to the other realities of your life with him, he was controlling, he was violent, you were abused by him. And you don't (nobody does!) deserve to be put in that situation.
I mean, you've probably walked down the path of "it's my fault", "if I'd have done....", "why couldn't I be.....", "he's got so much to handle"................ now and then, right?? which may color your picture of what he was really like at times.
But you do know the truth and you can/will be so much stronger without him. It might take a little time to "put yourself back together" to "put things more in the past" to adjust to a different kind of life, but at least you have to know that now you're safer and the children are safer without him around (or around so much if he still has contact with the children- something to think about later).
Now some more support for you!!: Do you think it would help you (if not right now, but soon?) to talk to other people who have been in the same situation?? You could always start this online if it's easier and there is a forum for survivors of abuse here as well you might like to try. And maybe if you talked a little more to your mom about what you've been going through??
But however tempting it might be to just give it "one more try" (and at points it might be!!) remember you've made the decision you have in your best interests. A very brave decision and well done, just hold onto that!!
If you want to talk more.................
Best wishes
Alison