I'm scared of brain tumor

I'm 18 years old and my life seemed great until I was diagnosed with anxiety. All the symptoms were something new to me and I was depressed for half an year, thinking I'll die of some illness cause all the symptoms seemed to me like symptoms to serious illnesses. I somehow realized that all the panic attacks I get, the shortened breath, the feeling like my heart is beating too fast (or sometimes too slow), the tachycardias and all the other stuff won't kill me and don't make me sick of illness, but there is this one thing I still can't get over - the head pains. I've done computer scans and checked everything possible - they didn't find anything, yet I still can't get the idea of having a brain tumor out of my head. I have this pain inside of my head, the right part mostly. It's not a headache that would go away with a pill, it's just a pain, sometimes a shooting pain, sometimes it feels like pressure or just a light pain. It also sometimes makes me wanna vomit, but it's just for a few seconds, the pain don't last longer than 10 seconds. I have this pain for 6 months, first it was here every single day and the thoughts I had were really killing me. The last 2 months it was better, now I get the pain in periods, 10 days no pain, then again, 10 days pain. How is it possible to show nothing on the scanning results and yet still to feel pain? I am so scared of having a brain tumor, it's destroying me every day!!!  Sorry for my bad english.

[remar]

I think a tumor would have showed up on a scan. Did you see a neurologist to have these tests done? I wish I could give you a definite answer. I do know headaches can come with anxiety and depression.  

[bbaggins]

Are you on any medications now or have you stopped taking any recently? If you stop most AD or anxiety meds suddenly, you can get the symptoms you speak of.