Well, first of all, if you regularly watch mainstream porn or Hollywood movies that have nudity in them, or you look at magazines containing that kind of stuff, stop. That shit’s not going to make you feel any better. It perpetuates totally unrealistic images of what bodies are supposed to look like. Real bodies don’t look like that, and are flawed and sometimes have parts that sag and parts that are lumpy.
Check out my Body Pride board on Pinterest for some photos of ladies with real bods. Also have a look at some body-positive blogs.
Do you masturbate? If not, please try to start. It will transform the way you feel about your sexuality and the wonderful things your body can do. If you want, you can even make it luxurious and almost ritualistic: get a nice sex toy, or do it in the bath by candlelight, or read some foxy erotica before and during.
If you need to have sex in the dark, at least for the first few times, that’s okay. No one can fault you for being insecure; we live in a culture that breeds those feelings. It might help to explain to your partner why you want to have sex with the lights off, so (s)he can help reassure you of your beauty.
When I feel insecure about my body, I go one of two ways: either I get totally naked, stare at myself in the mirror, and make a list of things I like about my body, or I put on clothes that make me feel sexy and feminine and go for a walk. Either way, someone is loving and appreciating my body.
Please remember that your sexual partner is just delighted to be with you and to be able to touch you and see you. (S)he isn’t judging your body. Trust me. (S)he just feels lucky to be there.