Insecure due to being plus size.

I'm a size 12/14 and I do cross-fit 3 days per a week, but instill very uncomfortable with my body when it comes to intimacy with my spouse. I have recently lost roughly 20 pound, and now I'm at a plateau. Ever since the plateau, I've been feeling gross. But anyways, by question is for plus size women... Do you feel comfortable during sex with your body? Any tips or advice? My husband Is very supportive, I know that it's me. He would like me to wear lingerie, but I can't because I'm very uncomfortable. My husband is VERY fit. 
Please help! My husband has also experienced ED for the past 2 years, so that adds to my insecurities although he has explained over and over again that is not my fought.