what if daddy starts being violent towards your baby as well,
Yes, exactly. There's a lot of it in the news at the moment. Delikatna, you're not just responsible for yourself, you are responsible for this other life too.
The following is a quote from Olasz's third link:
Children in a home where the mother is being abused are also at greater risk of being abused themselves, or being used to control their mother. Due to his own lack of self-worth the abusive partner feels the need to control all those to whom he considers himself superior. In a family, this includes the children.
You can't change a guy like that. What sort of hold does he have over the other flatmates that they won't stand up and thump him one?
So get out of there girl. There are places you can go, even if you don't have anyone else in the UK.
PS - It says in your profile you speak Polish. Are you Polish? Or did you just learn the language?