Left side - throat

For the past 6 years, i have a problem in my throat that i cannot find a solution to. It's always on the left side, everything feels irritated from the (nose-throat connection) down to the esophagus. I feel like there is constant post-nasal drip, an urge to clean my throat, and when i do its a clear gewi substance. My left ear is also irritated constantly and sometimes it gets full. When i eat certain foods, or overeat it gets worst, smoke would make it super bad, and when i exercise that side is always dry. My partner has pointed out that there is also a foul smell coming from my mouth. The only thing i could think is the tonsils, but my tonsils do not look swollen, quite the opposite they are super small. I have been to many ENT doctors and they cannot find anything. I do not know what to do about it, this condition has made me have health anxiety and i always wonder what is it that i have. Its not going away! any suggestions?