Sorry to hear of your difficulties with dizziness! I can get vertigo easily myself (NO amusement park rides!!), and know how miserable it can make you feel!
I'm not sure how much I can add that may help, other than to say that I had an ear wax problem before I realized I had reflux. I didn't understand what was happening, and finally went to an ENT when I had lost hearing in one ear for two or three weeks. They vacuumed out the wax, and everything was fine...but a year later when I went back with significant reflux symptoms, he looked at my chart and said that's why I had the wax buildup. Sleeping flat allows the reflux to run up the eustachian tubes and cause irritation.
Having reflux requires us to be our own detectives, as doctors frequently are little help. What I would suggest is to get one of those foam wedges for reflux (Bed Bath & Beyond sells them), and see if your fluid symptoms improve. At any rate, it will reduce your other reflux symptoms by reducing your exposure.
I see you're taking a PPI, which is good. But getting good results from your PPI may not, by itself, reduce your ear problems...if they are in fact due to reflux. The reason is that PPIs only reduce acid, and not the non-acid components of reflux which can be almost as corrosive. That's why sleeping on the wedge will help you diagnose your problem.