Don't feel sexy 😞

My fiancé and I have been together for 4 years and he is the love of my life as I know I am to him. Since we have been together I have gained a lot of weight and I don't feel sexy anymore. I used to be pretty thin and now I'm close to 100lbs more. I don't feel sexy anymore which makes me not want to start anything regarding sex or want to be on top because I'm afraid I'm hurt him or I won't look flattering or anything like that 😭