allergies?

Hello I am 20 years old and in great health but I been having this problem for over a year now. I went to 3 different ENT and no one can find anything. I have had a CT scan, many ear tests, and camera in my nose, I have tried many allergy medications, sinus washes, nasal sprays and nothing seems to work.

So here my problem
My left ear has been bothering me. Some days I can feel fluid in my ear moving. Sometime I get a popping noise in my left ear also like there is air stuck. I tried popping my ears but that didn’t work. When I do yoga sometimes I can feel it draining to other parts of my face. The doctors can’t see any fluid in my ear but I can feel it there! Also I get sinus pressure on and off sometime I can go a week without it and it come back again. I get dizzy and feel off balance almost every day. I don’t have a runny nose but I wake up with it stuffed up. I get a lot of post nasal drip everyday. I’m clearing my throat all the time. The post nasal drip is always clear though. I’m starting to think it could be allergies but any allergy medication I take doesn’t seem to help. All that helps is Advil sinus and cold but I can’t take that everyday for the rest of my life. I made an appointment with an allergist so I guess see what happens from there.

Its just soo annoying because the sinus pressure can get real bad and its always usually just on one side of my face the left the same side where my ear bothers me

If anyone can help me and maybe tell me what they think it could be because no one can seem to help me.
That would be great thanks!