As a typical HDM, I can tell you that your attitude determines how you look to us. As others have said, you have to feel good about you. Do what makes you feel good about yourself and you won't have to worry about how others see you. They'll see you as super-hot!
Another thing about men: we love those who make us feel good about us. Your guy telling you that losing weight and buying new clothes will make things better in bed is him saying that he doesn't feel good about himself. Don't get me wrong, I think it's ok to make those requests of a spouse. But why don't you make a few, too? Like, "I'll be glad to lose some weight and buy new clothes. How about you doing some reading on new techniques in bed at the same time? That way we'll both be better for each other."
You also have to be realistic enough to know if he's just making another excuse or making a legitimate request. He may be one that you can't please no matter what you do. (Speaking from experience on this one!) In that case, you still have to do what's right for you.
Btw, I've never seen a woman who wasn't beautiful in some way.
