Sex marriage weight gain

Soo my husband hasn’t been having sex with me but he is affectionate in every other way so when I finally asked him why it stopped he said he isn’t attracted to me or turned on by me any more because I’ve gained weight. I don’t think I’m huge but I could lose some weight. It hurt my feelings that he isn’t attracted to me anymore and now I’m in sexless marriage. I have a thyroid condition that makes weight easy to gain and hard to lose. Idk I just feel like the love is conditional now and I know I’m going to lose the weight but I’m not sure how I’m going to feel about him at the end of the process . I don’t know what to do but I go to bed fighting tears every night.