Heartbroken from a relationship that never was. Reddit, how do you deal with rejection or loneliness?

I met this guy back in January, and we casually talked a lot. I started to like him and taking his texts/comments in ways that he didnt mean. It probably didn't help that he is the quiet type who normally wouldn't speak whats on his mind. So overtime I convinced myself that he liked me, but that he was scared to admit it, as starting today our relationship would have to be long distance(moving for work).

So last night night, his friends, him, and I went to dinner, and it was probably the last time I'll ever see him . And he just said a simple bye and left. Its clear to me there was nothing there to begin with.

I guess you can call me rather bigger set despite having lost 50 lbs (40 more to go). I am very dedicated to school and work, and I love challenges. And I failed with this one. Is it because I'm fat? How do I get over this? How do you get over failure, reddit?