Thanks a lot for your input. First of all i am really sorry to hear about your symptoms.
As per symptoms your problems sounds like eustachian tube dysfunction. The function of this tube is to equalize the pressure. specially in flight, this tube has to be efficient otherwise one can get symptoms like yours. Sinus inflammation is not necessarily related to it because eustachian tube alone can have dysfunction or sometime there is some anatomical anomaly in the tube which fails to equalize the pressure. It's also possible that one can feel the pressure behind nose and in head. Patulaous eustachian tube is one such condition in which no sinus inflammation is seen on CT scan.
Tympanometry is the test in which probes are put in ears (not headphones) and pressure is applied through the probe to see that is there any fluid in the ear and is the eustachian tube working fine. The test you have mentioned is called pure tone audiometry. So please confirm that if you have got tympanometry so far, you should get one because it's the deciding test that what can be done for you.
There are two types of treatment for this problem. First is medical treatment which includes steroid nasal spray like you have got. Then decongestant nasal spray like xylometazoline nasal spray two puffs thrice daily for seven days, tab sudafed twice daily for two weeks and steam inhalation with menthol drops twice daily for two weeks is required. Fortunately except steroid nasal spray the other drugs are over the counter available and i advise my patients to use them, Moreover i advise my patients to use xylometazoline nasal spray just before flight and just before landing. Lastly i as them to take OTC tab sudafed before flight too. These medicines should not be used by high blood pressure
or heart patients. If the medical treatment fails then grommet tubes can be put in the ears and they give immediate relief.
I wish you good luck that you get well soon, please ask if you have any question because our discussion always remains open so you can always ask more till you are satisfied, You can click the smiley to rate the answer. You can come back here to ask anything even after you have rated the answer. I will be glad to help you always.