You have a lot to consider and you have a lot going on. But consider making a plan for yourself. There are things you'll have to compromise and sacrifice but valuing yourself and having peace should not be one of those things. Not everything has to be permanent. It is okay if something doesn't work out, there are always other options.
If you would get £750 housing benefit plus £1900 and rent is likely to be £1200, wouldn't that leave you with £1450 for bills, food. Isn't that enough to get by until kids are all in school? Do you think the father would avoid any financial contributions and be able to evade child support? Even if that amount is not what you are accustomed to, I'd rather live on less than live unhappily, and like you say, you picked up on a bad parental dynamic as a kid, and you don't want that for them. X
So, a few questions: How old are your kids? Does it have to be a 3 bedroom? Does it have to be a house? Baby would end up sharing with you to start, so couldn't you go with a 2 bedroom? At least for now and then when you are working again move to a bigger place. Depending on your kids' ages, you could have years until you would need an extra room. I live in a one bedroom with my partner and our 3 year old. Is it comfortable? Not really. Is it doable though, absolutely. Also, who owns your current house? If you aren't happy, your children can sense that. They see your relationship and what is going on. Personally, I'd leave. Sorry you are going through this OP.
£2650/ month AFTER TAX is the equivalent of an extremely good wage. Plus, possibly child maintenance payments. I'm struggling to see how you would struggle to cope? It definitely isn't the block to you leaving
@Rhiannon yes the money I would be able to live on just fine. No I don’t think their dad would avoid paying for them, he is a good dad I have to say. I just remember how I felt as a child with so much bad energy around ☹️
@Hannah my kids are 9 and 3. It doesn’t have to be 3 bedrooms my 2 elder ones can share. My current house is privately rented.
@Katie yes I suppose you’re right, I’ve never been a sole provider it’s always been my partner I just bring in money for the smaller bills so I’m just worrying if it’s not enough but I could live on that money just fine with my children
Ah, your 9 year old would probably want privacy sooner rather than later, so it's understandable that you'd prefer 3 bedrooms. Why are you feeling trapped? If you, financially, could move and rent your own place or move in with your mum, and you're unhappy in your relationship and want to leave, why wouldn't you?
Personally, I think you need to listen to what you want/need long-term. No one can know and weigh your personal experiences and circumstances, but if you are truly unhappy and the relationship is toxic, you know what you will need to do.