Ringing in both ears.

i am a 30 year old female with ringing in both ears since March. It started out as a sore neck and sinus pressure and then the ringing in the ears started. I have been to an ent and had hearing tests that showed no hearing loss. However, both of my eustachian tubes were shown to be barely functioning. my ringing was such a high pitch that the audiologist didnt even have the tone in his system. I have been on steroids, nasal steroids, antibiotics(for aan ear and sinus infection he found while treating me) plus I had an allergy test that showed major allergies to 12 things although I have never had any classic symptoms. So now I have been on allegy shots for 2 months with no change.My ears continue to ring and are stuffy and it is driving me nuts! I can shut my mouth and nose and blow and the tubes open and then shut right back. I also have popping constantly. My question is, did this ent diagnose me correct. I am worried i have a brain tumor or something. This is the only ent in my area.