My recently long distance boyfriend broke up with me with no definite answer

My boyfriend of six months broke up with me.  We have known each other for almost four years.  I have been in love with him since the day I met him.  And there has always been signs that we should be together, it was just always the wrong time because we were with someone else.  We started dating and everything was wonderful.  He was the one that initiated everything.  Before we had started dating I believed he was the man I was going to spend the rest of my life with and still do.  He told me that I was the woman of his dreams and all that special stuff.  I remained kind of reserved for a while as to whether or not I was going to believe that.  But the look in the pictures of us always made me believe him, because I do not believe you can fake that.  Well a month ago he left to go to Alaska for five months.  He is 4000 miles away from me.  He told me before we left that he had tried to distance himself in the week prior to leaving because he had finally realized just how much he was going to miss me and just how much it was going to hurt.  Two days after he left he told me that he was not going to even masturbate and that he wanted to keep the no sex thing up until after he got back just to see how long it could go, and I was like okay, but if that's what you want.  I thought it was another instance to help him be defensice to ease the pain.  Well everything was fine for the first few weeks he was there, until we got into a bit of an argument.  It wasn't anything malicious or hurtful, more of a disagreement of the situation.  He told me that he loved me, but he thought we were the best of friends, but I wasn't doing anything wrong, but he did not know how he was supposed to feel, but he still loved me.  Well after that I just tried to stay positive and supportive.  He works 12-15 hours a days 6-7 days a week.  Then last Thursday he calls me and starts rambling and then says that he loves me and that we are extremely compatible but he doesn't know how he is supposed to be feeling, but he doesn't know if he could ever go a few days without talking to me, but he doesn't know what he wants, but he cannot live without me as a part of his life, but he feels he has to choose his career or me.  I told him that he had to decide.  I still love him and that it was his choice.  We go to get off the phone and I am crying and then there is a long pause which was followed by my saying that I wished he would have said he loved me to which he replied he was going to but did not know if that would make the situation worse.  The next evening he sent me an email stating that he will always love the wonderful person that I am and that I should not feel betrayed and unloved.  he tells me that he feels he cannot be what he thinks I need right now.  He also said he feels that he needs to focus on his career.  He also said he did not think that his feelings would have changed as much as they did since he left.  He said that he looks forward to the next time he gets to hear my voice.  And that he wants me to remain as a part of his life.  I called him and was hysterical, and the next day he messaged me online thinking an old message was actually one I had just sent.  I told him not to give me false hopes and that I still loved him and that he may call me when he learns something, or becomes a man, or if he truly needs me.

I am so confused.  It is hard for me to believe that you just fall out of love.  My gut instinct tells me that he is just scared of failing and of committment.  I sent him an email telling him nothing made sense.  He never gave me a definite answer and I told him that once he returns that he can come home to me and always will have a home with me, he just has to work for it a little more next time.  I do not know what to make of the situation.  I am not contacting him.  He comes back in September.  I just do not know what to do.  Does he still love me?  Is he confused?  Is he scared?  We were almost at the next step... he started talking about marriage first and soon we both were and it was never awkward.  I don't know what to do.