Home or away... Uni? Im really confused on what to do.?

I don't have the greatest life living at home. I have a very nagging older sister who stayed home for university and she's in her 2nd year who keeps a watch on what ever I do (very annoying) and my parents argue a lot and I also have the smallest room possible. I live in a very small village north of Cardiff in a rural area (a place where you wake up to cows and chickens in the morning lol) and all my friends from school live at least 30mins away as I go to school in Llandaff which is in the middle of Cardiff so I have a very boring life too. I go to university next year and Im getting that question, should I stay home and safe my self the debt or go to university far enough from home that I will be able to move out. My parents want me to stay home over issues of finance. I've looked at what finance will be available though, living in Wales even if I move to England my fees will still be 3k a year, I want to go to Bristol and that will cost me about 5-6k a year for accommodation etc perhaps more depending on what happens with inflation and the economy. I've read that depending on household income if I decide to move away I should get a living grant of around 1 thousand a year. My parents joint income is around 35k so Im not sure if Im just out of that bracket. I know with the students loans I wont pay anything back until Im earning 21k but its still a loan and I got that nagging feeling do I really want to start my life with 20-30k of debt before I even have a mortgage etc.What do people reckon, I know my social life will be far better than living home but is it worth it? I really don't know what to do.