A brain tumor wouldn't linger like that for 10 years. No way. No how.
It actually has to be pretty sizable to have you start feeling symptoms in first place, so after 10 years.... yeah, you'd have your brains sprouting out of your ears and nose. You would have much, much worse issues going on right now if it were a tumor.
So, a tumor is out of the running. Now, what can do all of that and COULD have been around for all of these years? Anxiety!