Thank you all for your help. But still after almost 6 months of first symptom, i don't feel any better, I still have the head pressure (no headache), feeling like dizzy (not like i am going to faint, more like the feeling you blow a balloon and after that you feel dizzy or pressure in head for a few seconds) but mine is during the whole day, except for when i am laying down. To explain better it is something in between Dizziness, Foggy feeling, pressure in head, cannot focus, get tired soon after short walking.
I have done all kind of tests (blood, urine, MRI, Hepatitis, HIV, and whatever you can think of, except inner ear, which my doctor think my symptoms are not similar to inner ear problems (he says symptoms should be strong dizziness like you can't even walk). I also tried Clonazepam (Anti anxiety) occasionally to see if it fixes the problem , but didn't do much.
Please help me if you have any good suggestion, and please don't tell me it is dehydration or something like that, because after 6 months i have tried everything you can think of.