Write down all the positive things you love about him
Try to think of him in those ways (e.g. caring, friendly) and train your brain to bring up that kind of image every time you think of him.
If you cannot overlook the overweightness, talk to him about it in a sensitive way
If he is prepared to loose it, you will know that it is worth going to these lengths
If he dumps you for being shallow, he was not worth it anyway as he is selfish and does not want to do anything for you. The relationship would have been one-sided and unfair.
when his love is pure kind and sweet. there are no violence, put downs and adultery. love is patent. and it doesn't hurt. he is being a man when he shows all of the stuff above.