Re: What could this be?
It sounds like you may have more than one thing going on.
The dizziness sounds like vertigo which is basically an imbalance of fluids in your inner ear close to your semi-circular canals for balance, often caused by a mild infection or excess fluid. Eliminating salt from your diet can often help this. However, vertigo can be a symptom of other conditions, or it can stand alone.
The nausea can be caused by vertigo, or it could be a symptom that you have along with the vertigo.
You really need blood tests and a physical examination to determine what might be causing these symptoms. It's helpful to write down all the symptoms you can think of and bring those to your doctor. Even if you think it's insignificant, still write it down.