You have done the right thing, well done. I would start to get yourself used to the idea that it is over.
Even IF (and it's a very big if) he received the necessary professional help and support, and really worked through it, and completely changed his personality - it wouldn't change the facts of what he's done to you. It wouldn't alter the fact that you had to leave him for him to make any effort to change. It would change the fact that your children are frightened of him and won't ever fully trust him.
And that's if he managed to change (and not temporary change, the type that lasts a few weeks, just long enough to reel you back in, then they go back to their old ways).
If he really wanted to change, he'd have made efforts before now. He wouldn't have treated you as he did. He wouldn't have frightened your children.
There is a really good chance that his attempts won't succeed. And that's all on him. Don't let him guilt-trip you and make your feel responsible (I had all the 'if you were more supportive I'd be a better person'; 'my counsellor says you should be more trusting of me'; 'if you let me move back in I'd recover faster' nonsense). No, he gets himself better, and on his own time, under his own steam.
If in 3 or 4 years from now he's a sustained, reformed character, a thoroughly decent human being, then you might be able to have a positive relationship with him. There's a decent change he'll expect to go to 3 therpay sessions and read a chapter from one book and think you should forigve him and move on.
Please stay away from him, and make it permanent, for your sake and mostly your children's.