Help....

my SO and I have been together 2 years, and are getting married in October. i have finally been able to get my diabetes under control, and I have started losing weight. ever since that has begun our sex life has dropped. it used to be 2 to 4 times a week, now I'm lucky if its twice a month. he is nothing but kind, sweet, affectionate, and i trust him completely, but i feel like he doesn't find me attractive anymore....I'm lost and i don't know what to do. we have talked about it many times and he reassures me, but I'm so worried I'm going to lose him....help....(here is a picture of me when I was with my ex 1 year before i met my SO, and one from a few weeks ago)