I would definitely see a doctor soon. It's best to get faintness checked out. I would also ask to have the heart monitor for more than one night because, as you say, it didn't happen the one night you were wearing it.
Hello~
Your symptoms sound quite serious, I would see another doctor, preferably a cardiologist, you need to see a specialist instead of a regular GP, this is nothing to wait around with.
I will say that some of this sounds anxiety related, is your stress level high? You may be having a reaction to your inhaler, sometimes our bodies can suddenly develop a sensitivity to the meds you are on.
If, after having a thorough check up for these issues, and nothing is found, then see a chiropractor, believe it or not, when certain vertebrae I the neck and upper back are out of alignment, you can have these symptoms.