You already know there's nothing wrong with your body, you just need to find a way to make yourself believe it.
FYI, I empathise with your anesthetized emptiness. It's what happens when you've lived to long in a restrictive environment at some point you loose yourself. If you move out, get mental space, you can get connected again.
EDIT: I think the question you need to ask yourself is: How come is it that people who are clearly less ideally shaped than me somehow manage to be happier than me?