HELP! Stuck in that strange after high school starting college phase

Towards the end of high school I got a new job and saved all my money and traveled to Brazil with my boy friend for three months. I didn't have time to see my friends because I was working a lot and then I left and didn't have any way of contacting them. I lost touch with everyone and friendships dissolved. Now I pretty much have no one besides my bf, I am usually busy working or studying but I feel lonely and I feel so pathetic but I honestly don't know how to get back into making new friends. It's not like high school where everyone is in one building all the time. It's even more difficult because I feel like this is so stupid but it's actually a problem. I miss going out with friends and getting out of my head. Any advice please?