Don't feel sexy

Just sent my hubby a sexy picture and he kind of just brushed it off .. every time I try i send him something he doesn't seem interested .. ever since I gained weight it's like he doesn't find me sexy anymore .. I feel like sooner or later he's just going to cheat on me with someone skinny and more attractive then me .. when were out icatch him staring at other woman when they walk by and it just hurts so bad because I feel like im not beautiful enough .. I 've suffered from self esteem issues all of my life and him being my man I feel like he should be making me feel beautiful but instead I feel like an ugly fat woman ...