My youngest son is like this, and he's a nurse! Seriously, you need to find a good counselor because you need someone who is objective that you can bounce these feelings off of. Family will probably just poo poo it or encourage you further in sympathy (your mother for example). You have to learn to trust your body; it wants to be healthy and that is it's natural state, despite all of the abuse we visit on it. Take heart, you can overcome this.
"There is no use trying,"said Alice; "One can't believe impossible things." "I dare say you haven't had much practice," said the Queen. "When I was your age, I always did it for half an hour a day. Why, sometimes I've believed as many as six impossible things before breakfast."