You might be suffering from obsession , obsessive thoughts. These thoughts invaribly cause anxiety. The psychiatric definition of obsession is unpleasant, unwanted thoughts that one is constantly thinking. You might be a hypochondriac. I could be wrong in both my thoughts here . I think your best option is to talk to your primary or who ever you see for general heatlh care Then if needed see if s/he can refer to a specialist.
My suggestion would be to seek therapy, to find out why you have this destructive anxiety.