Hi, Raging Panda, and welcome to PC.

I'm sorry to hear about you losing your girlfriend and best friend. As an introvert myself I know how hard it is to replace those relationships, especially ones that are really supportive. Through the years I lost a lot of good friends that I used to be able to discuss deep subjects with. I remember and miss them from time to time.

I'm going to say something that may sound contradictory, so here goes. On the one hand, it's okay to feel sad for those losses. Give yourself time to mourn them properly and let them go. On the other hand, keep working on those new college friendships and find other groups that interest you. If nothing interests you right now look at volunteering at a charity or non-profit organization. Do something to keep from getting too isolated and lonely. If you start feeling seriously depressed see if your college has counseling services available. You may need support from a professional until you get through your depression and build your new friendships.

I hope you get through this rough spot in your life. And keep posting.