Guys, do you understand his actions?

Okay, so October 2012 I began talking to a guy I had gone to high school with (he's 2 years older than me) and we hung out a few times. He seemed to like me and I liked him but it kind of just died off around january 2013. I moved across the country in feb without almost any notice. One getting to Maryland a few months later in April he and I got in touch again and really hit it off. We text/talked everyday and things got serious. We continued to be very close until Dec 2013 and I went back home to visit him for 2 weeks for Christmas. It was amazing and emotional for both of us. We took a mini vacation while I was there to see a Christmas town and he asked me to be his girlfriend. I could tell he had some doubts about the distance but I had every intention of moving back to him soon. He isn't a player or anything like that I assure you. I met his fam and they loved me and when the 31st rolled around it was very sad for both of us. He said he still wanted to give it a try. Only 2 days after I was back in MD he was acting distant and depressed like and hardly talking to me. I confronted him and he said he couldn't do it and since then he won't even respond to my texts. It left me with no closure and I'm still hurting even though it's nearly May.

What do you think is going on in his head? Does he just not care anymore? :(