So I've been suffering from this brain tumor fear for the last year and a half on and off. This entire month I've had this constant headache in the back of my head thay won't go away no matter what I take. I had an mri and a cat scan may of 2015. Over the last week I have become nauseous and I just feel weak. The chances of a brain tumor growing since may of 2015 are probably slim to none but I can't think rationally for some reason.