Is it real?
The answer is yes. The first drug I was on ABVD actually, it is a combination of 4 drugs which did it for me. I smelled it when no one else did, not even the chemo nurse. Yet I can tell you the A, Adriamycin smells also identical to the toilet bowl cleaner, Mr. Duck. Years later if I used that toilet bowl cleaner I would be cleaning the toilet again for it would make me throw up.
I would smell the drugs if they were being used elsewhere in the room and I could get sick just thinking about it.
It is real and not in your head. The technical term for it is, cyclical vomiting. I never found a way to deal with this.