Have you guys sent pictures to each other?
I think you should tell him EXACTLY what you told us and if he ends it then it was not meant to be. I know exactly how you feel, it feels so good to hear some of the things and its exciting he is saying sweet things to you but the fact that you already need a break after 4 days is a sign.

Just tell him how you feel. I would leave the overweight part out. I mean what is normal weight anyways? Also, if looks are so important to him I would def make him fly out to see you. Let him waste his money so to speak. How far away is he?