I don't think mine is quite the same, but one of the first symptoms of mine that took me repeatedly to the doctor was maybe simular? It would happen under certain situations where I would all of a sudden feel like I was floating and that the world was whizzing around me and I was no longer in sync with everything that was going on around me.
After a while I chalked it up to an anxiety attack but it wasn't. However; when the feeling started...then I would have an anxiety episode!! I used to tell the doc that it was like I was moving in a different direction than everyone around me. I didn't feel sad or cry....just afraid especially when I was driving. I get it in the grocery store while moving down the isles and looking to the side and under flurescent lights. Doc does think its an MS thing. And yes, tell your doc even though you feel looney. Just tell your doc that you are afraid of admitting it. When I finally told a doc what was happening to me, I fell into his arms sobbing......the feeling tormented me. No I was not nuts and neither are you. Big Hugs and be sure to tell your doctor.