What do you think happend? ..the love of my life is completely ignoring me.?

okay so i've been talking to this guy for a while now ..we're not official 'boyfriend girlfriend' ..we're not going outt or anything but we're together.. or were =/ anyway, he just got back from boot camp and is now a US Marine. i know its hard having a relationship in this situation but thats not even my point. while he was away, we wrote to each other and all that and he acutally wanted me to come to his graduation. [mee, out of all people ..who woulda thought] .. i was happy .. and i actually went .. i flew to south carolina with his family to see him. we got back a few days ago and hes been ignoring me ever since. and the thing is i have no idea why! he isnt answering my phone calls, my text messages, my IMs .. NOTHING! could i have done something wrong? i dont think i have... but i'm going crazy i have no idea what is going on! i mean, if he doesnt like me anymore or if something else is going on i just wish he could at least talk to me about it instead of ignoring me..