Feeling dizy for last 4 months. Is this?

I have been feeling dizzy for last four months. First, I thought it is positional vertigo. But it wasn't. Then I got checked my blood.it was normal. Brain mri was clear. Then the Dr. Told that it might be a case of cervical. The neck x Ray was also normal. Then I went to cardiologist. Got checked my blood pressure 10 times a day. That was also not the problem. And now I am being told that it might be a case of anxiety. What should I do. I feel a little dizzy.  some days the dizziness go away. When I was at home for 20 day. It was very less. When I am in the city I study, sitting in my room. I feel dizzy again. When I go out, for some time the dizziness persist. But after some time it goes away. Please help me,and tell me which problem is this??