What Causes Mild Vertigo Through Out The Day Along With Fluid Build Up In Ears?

I have mild vertigo. Usually noticeable most of the day. No nausea or vomiting or any other symptoms. I am not lightheaded nor do I feel faint. Other than the vertigo, I feel completely healthy. Went to urgent care about a month ago. Was told fluid buildup was in one of my ears and no ear infection. They prescribed nasonex. I don t think that really helped. How long can the symptoms last and how long should I wait before going back to the doctor?