You will make new friends, this wont last forever.
He was not your friend, he abused you. He might have listened to you, though frankly I find that a little unlikely, but he would also control you and hurt you. No friend is worth violence and control. You will find new friends who will listen to you and spend time with you because they like you. They wont hurt you, they wont control you.
Just try and make it through each day as it comes. Try not to focus on the long run for the moment, just get through each day however you can. This is a very difficult point, but it will pass. There is a end to this in sight, there is no end to the abuse if you go back.
Perhaps you have been institutionalized by his control? By which I mean, you have come to find his control perversely comforting and without it you feel lost. If you haven't already seen it, I recommend you watch The Shawshank Redemption, it compassionately describes the effects of institutionalization, it might help you understand your feelings, and besides which it's a brilliant film.
Again, I urge you to find someone else to support you. Friends, family, support workers, the Samaritans, anyone. Take the kids out for a walk, go see a movie with them, go to a playgroup, or even a local softplay centre where you can let them loose and have an hour to yourself. Try to do one nice thing for yourself every day.
Finally, please think of the consequences of returning before you do anything rash. The social services involvement and the possible consequences for your kids, the violence, the emotional abuse of your kids, living in fear, having no freedom. You and your kids deserve better.