Stay off the internet -- symptoms you find there can apply to thousands of things and nothing. Once you get a diagnosis it can be helpful to double check the quality of the medical advice you're getting, but to just Google symptoms will drive you nuts. And Illness doesn't cause anxiety, it causes fear and worry. Anxiety is baseless, and since you have no reason to suspect you have anything wrong with you given what the doctors have told you -- yeah, they could be wrong, nobody can tell you they aren't in 100% certainty but nothing else in your life is certain either and that's not bothering you, right -- then right now your problem is anxiety. That's what you need to work on. Maybe time to see a therapist to see why you're thinking this way and to learn how not to and see if that works for you.