Feeling depressed at uni

Hi I'm currently in my first year at uni but I'm feeling unhappy socially to the point that it's making me feel depressed and lonely. At first, things were great and I found a good group of friends on my course and in my halls, but now everything has started to go downhill as my friends from halls have started doing their own thing and one of my best friends on the course has told me she's dropping out over Christmas.

I've tried to make more friends but I got in a really small set of halls which is mostly occupied by international and mature students. I've tried to make friends from the main student halls, but as they live so far away from me, I feel isolated and it's hard to form strong friendships to the point that I feel like an acquaintance to everyone. I've tried to get a move to different halls but they've said I can't do it until after Christmas. I just feel like even if I did move, everyone has formed their main friendship groups and it would be difficult to find new friends. I really don't know what to do as I really enjoy the course and don't want to drop out yet I feel so isolated and just feel like everyone else is having a better time than me.