With the fluid gone and humming and dizziness present I I suggest you get referred to an ENT to get proper care. I lost hearing in one ear in 2004. I know many who have had ear problems like yours. Most turn out okay but some, like mine, progress into total hearing loss. Mine started as ringing and progressed to dizziness then eventually total loss.
The Shea Clinic is the best in the US, maybe the world. It’s in Memphis, TN.
With the ear it is imperative you get the problem addressed as soon as possible because, if it is serious, then treatment right away has a high success rate. I know 3 people that went to Shea and their diagnostics were superior to the one I went to. They’re unmatched, like that of Mayo for other diseases. The treatment at other ENT’s is very similar and limited depending on the problem So a good ENT should work.
It might just be fluid build-up but could be something more.