It's really hard to start over like that. It's not going to be easy. I once had to do that and ended up with no friends for three years, ending only in a chance coincidence involving the internet.
On that note, the internet really is going to be your best bet, unless you happen to be a drinking and pool playing type, in which case you should try to meet people in bars.
Perhaps you're lucky enough to have a club that interests you in your university? Look into it!