Sounds like obsessive thinking, which is definatly anxiety producing.
If you have seen doctor's and gotten results, you can trust the tests.
Instead of obsessing about a thought or syptom, try to pry yourself off the couch (at least that is where I feel myself sink into obsessive depressing thoughts) and go out to do something positive for yourself.
I find myself in the mountains nearly everyday, or I go trout fishing.
Take your vitamins, and eat healthy,,,think good thoughts about yourself and others around you. It feels so good to say positive things to other people....Tell someone (i tell my dog :roll: ) how beautiful they are, and how much you love feeling their energy.
Good times are coming, and don't you forget it!