He doesn't care to get me off

My husband and I have been dating 6 years and married 1. I love him dearly but he doesn't care to have sex and when we do he fucks me from behind only and he is the only one that gets off. It lasts at most 5 minutes and he never tries to please me after the fact. He claims he is too tired, his mouth hurts, or he simply doesn't want to continue to please me. My sex life before him was amazing and now it is horrible. I'll suck him off any day of the week but he won't touch me. I don't understand it. He never tells me I beautiful, pretty, ect. All he will do is smack my ass. I just want to know why I am not worth his time to please. Ugh someone give me advice. I feel like it's because I'm not as skinny as I used to be.. I have talked to him about it but he always changes the subject. I've cried in front of him about it as it hurts my feelings but he tells me there is nothing to cry about. He used to please me the first year or two but not anymore.