Hi OP, I haven't been through exactly what you have, but I understand what you mean. I've come from a modest middle-class family living in the north, and going to University was quite a change. There are quite a few "richer" families and a lot of people talked about private school, and I'm also the first person out of my family to go to University. My parents came from a very very poor family, so they've never had the "luxury" of going to University. I know your situation is a lot more extreme though, because it affects how you see yourself, almost living separate "lives". My boyfriend is going to Durham this year, and he comes from a working class family, the first person in his family to go to University, so I expect he'll feel the same as you. All I can say OP, is to enjoy your time with your two different groups of friends; it's not that you're not acting like the "real you", it's just that you have to adapt to talk to different kinds of people.