Why won't he call/text me back?

So I am working at a camp this summer for three months. About a month ago, I met a guy named James who lives in a small town a few miles up the road. We really hit it off. He got my number, and we ended up going on our first official date a few days later. Everything had been going really well, and we began spending a lot of time together, like 4 out the 7 nights of the week we were together. In august, I have to leave to go back to college and I will be 5 hours away from him. Last thursday night, he told me that I was very special to him, and he wants to move to the town I go to college in come August. The following friday night, I was suppose to meet his parents, but I was unable to because a situation arose and I couldn't. It was rescheduled that I would meet his parents saturday night. The following saturday night at 6:30, he stopped by my work and he told me that after I got done with work I should call/text him. I got off work at 8:30 texted him, and I asked what he was up to because I was off work. He never responsed, and monday I texted him again and asked how is weekend was. Yesterday I called him, worried that something maybe wrong. The phone rang, and then went to voicemail. He never called or texted me back. I don't understand what I did wrong, and how someone can act one way, and then completely start ignoring me the next day. I am super confused. Am overreacting? Could something be wrong, and maybe he just wants his space? Or is this a sign that I just need to give up on him, and just move on? Thanks for the advice!!!