Chronic dizziness or light-headedness episodes for 3 years, what could be the cause of this?

Hi, so I have been experiencing "spells" of some kinds of dizziness for quite some time. I started about 3 years ago while at work taking an order with pen and paper (no real physical strains or moves) When all of a sudden, I get this intense feeling of dizziness come over me, so much so that I almost fell over, but didn't as I grabbed on to a rail of some sort. This "spell" that I felt was not a "spinning" sensation, nor could I see any spinning, it just kind of felt like a magnet was pulling me down with such force, or as if I was moving in one direction, even though I was standing still, and there was most definitely not any spinning! This episode lasted for about 25 -30 seconds and then i felt completely normal again. Anyways, ever since that experience, I continued to get the spells that last 30 seconds and they would come every month at least once a month, then after that it was every couple of weeks, now i get them every single day...it is so horrible..! On occasion, I would sometimes get a very similar spell, but instead of the moving feeling, I actually have the true vertigo with the room spinning, theses spinning episodes when on about the same amount of time (30 seconds) but some last almost 2 minutes! I have only ever had 4 "room spinning spells" the rest are all the moving to the ground sensation as I previously stated. I also on the occasion get a feeling of light-headedness that can last for hours to even days, and then just disappear as mysteriously as it appeared. All of these dizzy spells I get rarely are brought on by head movement, I can be lying dead still in bed and all of a sudden, "The spell is here with a vengeance"!  Can I also just add, I have been self cracking/popping/self-manipulating  my neck for about 12 years now,  one time I “cracked” my neck really fast that I felt light-headed for a whole week and my neck was in lots of pain.

In the past I have had SO many tests to find the cause of my dizziness and NOTHING has ever come back positive for an illness. I have had:
MRI's Spinal and brain (2 years ago) = No bad findings
CT-scan of brain (2 years ago) = No bad findings
EEG=No bad findings
ECG=No bad findings
EMG=No bad findings
24 hour halter =No bad findings
Full blood count = No bad findings
ANA bloods =No bad findings
Cervical X-rays = Bad reversal of the cervical lordosis but otherwise, No bad findings
The only tests I haven't done are visiting an ENT to investigate, I am going to my Dr, tomorrow to try and get a referral.

Please, any ideas as to what is going on?
These spells are really taking a toll on my life, the quality of my life is very poor due to these spells, i can't drive because i almost crashed the car during a "spell" etc, the list of limits i have go on...
Please help, i am desperate and feel like i am the only one in the world that has this...
Thanks..

[sam_amilia]

Any ideas?

[Londres70]

I would have Meniere's Disease ruled out by the ENT Specialist.