I want to live with my mum?

Well my mum and dad split when I was 4 and I had to stay with both of them for a different amount of time. When I was 7 to about 9 I stayed with my mum permanently. Then when i was 9 - present I live with my dad and his FREAKING GIRLFRIEND. They split because they always had arguments. I have to live with my dad because he makes much more money than my mum, he lives in a 4br. My mum lives in a 2br flat. To be honest, i dont care where she lives and how big it is. My sister Melissa is moving to uni soon so its gonna be me , my dad , Shauna (stepmum) and Rachel (my 3 year old half sis). It won't be the same cause i do not talk to any in the house apart from Mel. I think I need my mum in my life considering im 12 now, I even started my period last month and i told no one, i'd probably tell my mum but i only see her on Weekends. She was away in Columbia but she's coming back tonight ;]. I need some lady in my life who i love, and that's my mum, she;s my idol.