EUSTACHIAN TUBE DYSFUNCTION

[JORGELIU]

Doctor, for 10 months after a severe cold I been having this symptoms: clogged ears feeling, dulled hearing, (metals and crystal sounds are very dull),  feeling of preassure in my ears, and I feel a bit worse when it is cold, I have had some tests, including audiometry and it was for the most part normal, except my left ear that is at 30 db only at 8kh, My tympanogram showed an As type curve with a compliance at about 0.4 mm, and my ETF TEST shows no variation in preassure when I swallow or I blow with my nose closed, pneumatic otoscopy revealed my eardrums move fine, in the tunning fork test i can hear the sound much louder in my worse ear (left) doctor said I has ETD, My question is, according to the ETF test I have ETD, but is there anything else that could be causing my ETF TEST to fail that way? E.G. OTOSCLEROSIS or problems with my osscicles?. I was adviced to do the so called Eustachian Tube excercises, as chewing gum, or drink with a straw, blow with my nose pinched, etc, but it does nothing but make me feel worse, some times I feel pain, and many times I feel even more preassure in my ears after doing the excercises, but rarely I feel my hearing improves if at all, My main concern is damaging my ears with this autoinflation excercises, besides several times I went to the doctor after doing this ET excercises and doctor told me my eardrums looked red and adviced me to stop doing those excercises, My question is, Why, if my ETs are obstructed, then why my eardrums get hurt when I blow with my nose closed?,
I use to smoke 6 cigarretes a day, do you thik that could be contributing to my ETD?
Thanks doctor