Cant Figure Out My Dizziness???

HI, First i will give you a list of my symptoms than i will explain how long and what has been done about them. My symptoms are..

Pressure in the head and face
headaches 2-3 times a week around eyes
stuffy nose
dizzy 24-7
always coughing up mucus
ringing in both ears
fullness in both ears
feeling blank or spacing out alot.

Well this has been going on for over 3yrs. Now i am 21, since i was 17 1/2. I basically feel dizzy 24hrs a day 7days a week but every once in a while i will get these attacks where i feel completely out of it and like im gonna pass out. These attacks usually come about 1-2 times a week and last about 1-2 mins. I also get really bad pressure at my top forehead and around my eyes that litteraly feels like my head is gonna explode. I get headaches around the eyes and nose about 2-3 times a week. Not really bad headaches but enough to keep me home. I also have a stuffy nose to the point where i can hardly breath out of my nose almost everyday. Also i always have mucus in my throat where i have to cough it up all the time, this is worst in the morning when i first wake up, sometimes so bad where i can hardly talk unless i cough it up. I also get ringing in both ears followed with dimming hearing that last about 30secs and comes about 1-2 times a week. And last i always tend to space out alot. sometimes i space out and get that feeling like "What was i doing again"?. So heres what has been done so far. Well at first i thought it was just a sinus infection so ive been on antibiotics and decongestants like 3 times before and that didnt help, Also i found that i have high blood pressure which is under control with meds but i still feel dizzy. The test ive had done are a catscan aswell and x-ray of my sinuses which they said looked good, A ultrasound of my heart which they said was good. They checked my blood sugar and that was good, they also checked my oxygen to my head which they said was like 99.9% which is very good. I also have bad allergys in the spring season. So I also have a MRI coming up on the 18th so if that comes out good than i will be more confused as to what is causing my dizziness. But for some reason i keep leaning towards something wrong with my sinuses or ears but i would like to hear what others think first. Thank you.