Your friend is probably hurting because your current situation prevents you from spending time with each other the way you used to. I've been through this situation before where I've been the one without a partner and I really missed hanging out with my friend. However, it is possible to make it work. Despite the distance you can keep in touch in other ways aside from in person meet ups. Try to talk to your friend and give it another chance. If your friend doesn't want to continue the friendship at least you gave it a try and showed that you care.