I have self diagnosed phantosmia, where I smell cigarette smoke.
In various strength from someone walking past who have just smoked to someone blowing into an ashtray aimed into your face (yes that was "fun" back in the mid/late 80's in DK).
It is often that strong/real that it causes me to cough, like back when I was 9 and sneaked a puff from my folks cancer sticks. When it is bad I can't taste or smell anything but cigarette smoke.
I think I got the smell all the time, just got used to it. When it flares up it is at random times, haven't found a pattern like when drinking, it's cold or if it is food linked.
It started after I went to an ENT specialist* in 2015. After I had suffered with badly with middle ear infection for a long period. That taking sudafed daily like gumdrop didn't even touch.
The specialist gave me steroids which made everything worse - worse pain, length of time when it was REALLY bad, and nose gunk flow and I felt even worse with general energy etc. After a month I went back and the specialist said - I don't know why the steroids is making it worse and what do you want me to do.
Since I have had all the other test while looking into what was wrong with me with CT/MRI scans, blood tests and even eletro zapping of my nerves etc. I'm pretty sure it is not a stroke, head injury, brain tumor, neuroblastoma, Parkinson’s disease, epilepsy, Alzheimer’s disease as I haven't got any other signs of these issues just the god awful smell.
What I have read it's a serious bout of sinus infection or a nasty cold can cause these phantom smells, but they should disappear in a few weeks to month. There is various drugs you can take to remove it but by the sound of it, it isn't really the drug that helps - it is time. From reading online GP's don't really understand it and also don't want to give you these drugs.
The only thing I have found that removes this horrid smell is eating Fisherman's Friend.
* the final doctor/specialist I got send to and requested to see, in my 3+ years of trying to figure out with regards to the pain I had in my arms, remember that
https://yacf.co.uk/forum/index.php?topic=65523.0