To not go back to him..

[teafor2two]

I left my fiancé and took our 3 children in November. He turned his family against me, said I made him unhappy, I'd just had a baby and he said he only didn't dump me as I was pregnant.
I had been messaging someone (which turns out he knew as he'd snooped on my phone) on and off for a year or so. He was really just someone to talk to when I had fallen out with my fiancé. He knew he could be abusive and would say he'd help me if I wanted to leave him, but the messages were never sexual and never any photos.
I since started dating this man and he's lovely. He treats me well, makes me laugh and in contrast when he told his brother about us he said "good, she's a nice lass" when ex fiancé told his brother we were over he said to him "about time, I've always hated her"
Now ex says he's missing me and being a family the more time goes on, he can't sleep thinking about it and he can't bear if I got with this guy. He doesn't know obviously.
Do I give it a chance? But then I don't know.. I just don't. I do miss being a family.
Do I call it off and cut all ties with the new man to try to work it out as a family and be able to move back into our home?

Obviously you don’t go back.

Separate the two issues. Forget new man for a moment. Did your old relationship make you happy? Was it a healthy environment for your children to grow up in?

Doesn’t sound like it from your post.

Make that decision and then give yourself time and then move at the pace of a snail with new guy who might be amazing (in which case great!) or might have been ‘any port in a storm’ in which case, you can find that out and just be you (and the children).

I think you would be a fool to go back. You are doing so well! He sounds horrible to you and treated you badly. You say you miss being a family, but you and your DC already are. You left for many reasons, just keep reminding yourself of that.

I don't see that there's any possible benefit of going back.

Abusive man does not a family make. Your family has changed shape, it's fine. Ex is probably missing you skivvying for him. Ignore.

It sounds as though you only want to go back to him because you miss the idea of being a family, you don't actually miss the person. I think you need to take a step back and focus a little on yourself. I wouldn't go back to someone who is abusive or said terrible things about me to their family, because the air will never be clear. There will always be a stain. Wish you all the best.

Trust your gut, OP. Who do you think of when you first wake up in the morning? What scenario makes you feel the most anxious when you wake up?

Awkward with the ex brother if you get back together with the ex, but keep your head held high if you do. Nobody should ever say what he said when you split up - there's always a chance that you'd get back together. 'Hating' you is a dreadful thing to say.
Unfortunately, a lot of people say this sort of thing without thinking of the consequences.

He says he can't bear if I got with this guy. And I suspect that's what's at the heart of it. He means he can't bear the thought of you being with the other guy, not because he's missing you and loves you and wants to get back together, but because he can't bear the fact that you might move on and be happy. He doesn't actually want you back, he just doesn't want the other one to have you either and this is his way of trying to stop you being happy or finding someone else. He wants all the control.

Thank you!