Why do I feel this way anymore? Boyfriend is making me feel useless.?

I have been on the heavier side, lost a ton a weight, and gained some back since I can't go workout all the time due too health problems. He is starting to make me feel like dirt, and I am very conscious about my looks and my weight. It really hurts to know that he is insinuating that I am heavy,when i have been trying so so hard. I know all guys look at other females, I can live with that, but when he comes right out and says those things, it really hurts my feelings. Should I start to do reverse psycology on him and see how he feels. I try and show the positive sides of life, and really since he is mentioning more and more to me about my looks, it just makes me feel useless, and kinda puts me back to my depression mood. I want so much to be skinny like other girls, I want to live a normal life, but you know what I wished I knew how to be that kinda person.... I am overweight, not as bad as I was between 14-16 in womens..... I need help please....