Sorry to hear your troubles. I've had some minor ones of my own, so maybe relating my experiences can help you or someone reading this, in some way.
First, though, my opinion. I'm no medical professional, but AFAIK, asthma attacks are generally triggered by inhaling irritants. Also, someone who regularly inhales irritants is more susceptible to bronchitis. I find nicotine to be an irritant, and I can't even imagine vaping 54mg/ml while chasing a better throat hit. I have no doubt that it would send me into bronchial spasms, along with nicotine OD symptoms. High tolerance to the chemical in your system, or not, I believe that the contact with your lung tissue is inflaming your lungs too much at that level.
I think it's unfortunate that you went there, because now that you have had, and liked that experience, you will naturally compare any vape to that. Perhaps if you try something entirely different for a while, such as snus, you may be able to reset your vaping experience, at least somewhat. I'm not sure what the best course there is.
Anyway, I have had just a bit of a hard time getting into vaping. I started with a 80/20 pg/vg 16mg/ml gas station mini brand, and found that I got swift and severe symptoms from just vaping as I would have smoked about 4 cigarettes in 2 hours or so. Severe sore throat, headache, stomach upset, and my senses and mental state became altered, and not in an enjoyable way. This was quite alarming, as I had picked it up on the way in to work, and I am a shift supervisor. I immediately stopped using it, and since I recognized that most of the symptoms were consistent with dehydration, I started drinking a lot of water. My symptoms subsided fairly quickly, except for the sore throat.
I researched it a bit that night, and found that some are very sensitive to PG, and try to minimize it. I have to say that for the little bit that I used, for such a short period, to get such a severe reaction made me think about just dropping the idea, but I decided to try VG. I learned the reverse taryn spin to empty my cartomizer, and filled it with plain Humco VG, and vaped that fairly heavily the next day, while still smoking a bit less than I would have. I didn't bother me at all, and didn't cause even the slightest bit of any sign that I needed to increase my water intake beyond what was normal for me. That was the encouragement that I needed to continue on.
I went straight into DIY juice when I placed my first order for some decent vaping gear. I also bought one premixed 18mg/ml VG liquid to use immediately, but found it to be harsh on my throat, and it caused me to cough fairly often. I then tried mixing my first DIY juice from some 36mg/ml VG unflavored, with a flavoring from that same vendor, and got the same results. I soon figured out that the flavorings used and sold by that vendor were alcohol-based, and suspected that as the problem, so I ordered some PG-based flavorings.
After much experimenting with those, I've found that 20% PG is quite tolerable to me, and 10% or less does not bother me at all. Also, anything more than about 2 small drops of an alcohol-based flavoring per 10ml is annoying to me. Some flavorings also are irritating to me, such as vanilla and butterscotch.
I now use only alcohol-free flavorings, and prefer those that I can use at 10% by volume or less. The only ill effects that I suffer are a dry, stuffy nose if I exhale too much through my nose, so I limit that. I've recently been experimenting with using cotton wicks in place of the original ones, and I may be sensitive to that, but I haven't been able to conclusively determine that yet.
I've also tried a few DIY flavor extractions using VG, including
cinnamon, cocoa, coffee, and
tobacco. I find that the tobacco extraction seems to make my vaping slightly more satisfying. I occasionally use a small amount of the cinnamon extraction for a little bit more 'kick' in my vape. The coffee and cocoa are good flavors, but seem especially hard on atomizers, so I don't use them much.
So, it seems that you've found that a low-nic PG liquid seems to be OK for you. Perhaps you can add some extra kick to your vape with PGA, cinnamon, or some other flavor, without irritating your lungs as much. I don't know if that will work, but it's probably worth a try. Personally, I find 18mg/ml to give an acceptable TH most of the time. Maybe after smoking instead of vaping for awhile, switching back to vaping might yield a better result. I hope you can figure something out.
