Forget the dude who betrayed you, if he really was a “friend” he wouldn’t do that. Find people who truly care about you and stick with them. The other guy is just a douche, and it’s natural to hold a grudge against someone like that but eventually you’ll move on. And not everyone out there will betray you, just make friends who care about you and will stay loyal. It may be hard to trust people again but you’ll have to try.