You say your story is "not that bad" but it sounds really bad to me. You underwent emotional abuse, which is just as bad as physical abuse. But it's harder to understand that it's abuse and report it (especially when you're a child. If you don't have physical bruises, who's going to believe you?)

I am really glad you got away from her and now have a partner and baby. I think talking to your partner about what it was like for you growing up could help. Maybe let him read the post you made on here. It helped me understand what your mother is like, so it might help him too.

Do you have a restraining order against your mother? I'm wondering if that might help (although I'm in the US, so I'm not really sure how it works in the UK).