I don't have a problem in this area at all, I've got to be honest, but used to be a party planner and we were required to give 'sex tips' (not that I'm some kind of pro or anything).
Sounds to me like a lot of it is psychological- firstly, you don't sound particularly comfortable with yourself, or comfortable bringing up your situation.
You need to feel attractive. Maybe try dressing up? Get into good underwear and things. I lost 5 stone (I'm preg now so I'm a beached whale) but at the time I loved my body and loved dressing up in different things and it encouraged me to join a gym and get toned and experiment with the way I looked and felt. This could be an avenue to explore?
Secondly, you need to know your own body pretty well before you can expect anyone else to know it. I would suggest the best way to try it is to make a little effort, like make sure the bedroom's tidy, you have clean sheets etc etc, give yourself some time and explore. Don't feel silly, just enjoy yourself. And don't let yourself get frustrated. Maybe even try it in the bath with a few candles. Learn to feel sexy.
Third, sex aids. lovehoney.co.uk has a big selection. Try things you wouldn't normally go for and have a play!! Get some for just you to play with, and some to use together with your partner. He might enjoy the new excitement and so that'll make you feel hornier. Obviously if you present him with an 8 inch 'big ben' to use to satisfy you, he's going to feel fairly inadequate, so think about what shapes and different vibrations you'd like to try rather than huge stonking size.
Fourth- Try ANYTHING to make you both feel sexy and connect, as if you're not feeling anything, to some extent, that is going to be psychological as you have to be in right frame of mind to feel like that anyway. Chocolate body sauces, exotic films, sending each other saucey txts or pictures, or even talking to each other about what things you like. There's a whole world out there to explore without it being smutty or anything.
Obviously, you'd have to make quite an effort but it'll be worth it to start enjoying yourself, and why not? Try not to be stressed. And let your guard down so that you can easily try new things.
Hope this helps!!