Worndown, I sympathise, your situation sounds awful. I agree with everyone else's comments. I was a single parent for 2 years after leaving a relationship that was wrong for me. It wasn't at all abusive, but was not satisfying emotionally, intellectually or physically. There were many, many times when I thought about going back for all the wrong reasons, (money, security, loneliness) because it was hard. But I survived because:
I made friends with other single mums (and married mums). I cannot tell you how much these friendships helped me and meant to me. We would cook for each other, stay at each other's houses sometimes, share advice and moan together. We also took turns to sometimes give each other a break (although not as much as I would have liked!)
I tried and tried to maintain a civilised relationship with my ex and to ensure that ds saw his father. Since dh was very hurt that I'd left, this was hard as he ignored me and our son for the first year. However, he has since come round and we are good friends. He sees our son every other weekend, pays maintenance, takes him on holiday, calls him every day and has a very good relationship with him.
I wish I'd had more family support at the time, but my parents lived too far away. Even if your families are upset, it's your life and you should explain this and ask for their help and support if you can.
Look after yourself! Easier said than done sometimes when you're on your own, but I tried to get the odd night out. And I did drink too much the first six months, but then I got a grip and realised that it wasn't helping. (Glad this is anonymous!)
Money is a pain, but your ex will have to pay maintenance. See a solicitor about whether you could stay in the house since you are the main carer.
It's interesting that you say if you didn't have children you wouldn't hesitate to leave. I think that tells you something about the relationship.
So, my advice in the end is that it's hard, but it's worth it if you are in the wrong relationship. And I firmly believe that children are happier with one happy parent than two warring ones. Hope this helps. Good luck whatever you do.