i had something rather similar to that a year ago or so.....my doctor put it down to anxiety or stress...but he said it "might" be some trapped air in your lungs. The feeling I had was that I wasnt able to fill my lungs as fully as I wanted...like I needed to take more breaths than I wanted to...and this made me feel dizzy, because you actually DONT need to take that many breaths...so you are actually hyperventilating when you get dizzy.
if that sounds familiar...just try and relax over it, and it should be gone in a couple of days...max a week. If you've had it for over 2 weeks i'd definitely see a doctor