Losing friends

How do u get over losing a friend? Let me start off by sayinf that I've been going through a lot emotionally and I haven't really been myself. Anyway I was trying to Snapchat one of my guy friends and I noticed that unfriended me and won't respond to my texts. It seems out of the blue since we weren't in a fight or anything and everything seemed normal. I'm trying not to be upset about it but it still hurts. I guess what I want to know is how do I move on? (I'm in college if that helps)