It really sucks when a friend becomes distant. It's even worse when the distance is so great, you can't close the gap. When you text or call them with something that would excite them back in the day. Only for them to give a very dry response. Makes you wonder if no response would have been better... I've heard of the phrase friends come and go, but it hurts the most if you were very close. Every close friend has a core piece of you with them. Your friends define who you are. You are, who you hang with. Before this goes on to be any more depressing, just know this. If your friends are disappearing 1 by 1. Its either you, or them. And in any case, find new friends. You must move forward.