Why am I being ignored?

I have been talking to a guy for about 5 months now. We have always have been friends but somewhat reconnected a few months ago. Ever since then we have been talking every single day for 5 months. Texting, on the phone. He would write on my wall all the time and quote funny sayings we would say together. In my eyes it was perfect. He would tell me how he did not want to hurt me like the past guys who have hurt me. He told me I was all his, he told all of his friends about us and they wanted to meet me. He was in another state very far from mine these past few months so I did not get to actually hangout with him. But we still talked and he would always say when I come home it is going to be so perfect since we have waited so long and it will be so special. He told me how he really did not want to be single anymore and wanted to not be a big partier and settle down with me. I waited and kept talking to him for those 5 months since I have always been friends with him before and knew him well. Last Saturday he came home and I picked him up from the airport and it was great. We went to his friends house and he introduced me to them and I thought we were really going to get serious. The next morning we went home and I have not heard from him since. It has been exactly 1 week. I just don’t understand what happened or what caused him to go from talking to me every single day to not talking me at all. I have texted and called him but I got no reply every time. I asked one of his friends who was there the night we hungout and he said all he said about you to us was that he really liked you and was really happy. If someone is so happy why would they walk away from something? I am just very hurt and if he does not like me anymore I need some closure.