Dizziness/Lightheadedness

Hi,

We often hear that dizziness/lightheadedness is one of the most common symptoms of anxiety but does anyone else get it so severe on occasions that they actually fall to the ground and take several hours to recover from these dizzy spells.

This is exactly where I am at the moment and have been for as long as I can remember.
Dizziness/Lightheaded is usually the only symptom I get these days, I have suffered from panic attacks in the past but this is not such a huge issue anymore, its just the lightheadedness.

It can strike at random times though I feel usually linked to my overall energy levels on that day and lack of sleep etc..
The most recent one was very embarassing as I was in a major supermarket, a place where I shop on a weekly basis so should have been no cause for any anxiety yet I started getting these feelings of losing my balance and legs feeling tired not able to support myself. Eventually I just couldn't stand anymore and fell to the ground and was spotted by another shopper who alerted the store staff who came to my assistance. It was one of my more embarassing moments..

I have been to the GP several times, had blood tests done etc and been told that its anxiety but not been given anything for it..

Can anyone recommend any over the counter stuff that would actually be any good in reducing these situations...
I am also thinking of seeing a psychiatrist as I cannot live like this for the rest of my life.

Any suggestions would be appreciated.