I don't have that issue. I hear some people are allergic to PG. Maybe that's why you have a problem.
Regarding the bad "medicinal" taste i was getting with the stuff i mixed with Heartland Vapes PG, i tried vaping their PG straight with no flavor or nic as a test and the bad taste is coming from the PG. So i'm experimenting with other PGs. I vaped Essential Depot's PG and the taste is a little better (not much. That bad taste is still there just not as pronounced) but there is hardly any vapor.
I noticed that when i try eliquids from different vendors, sometimes i get that same weird taste. It must be from certain PGs. I don't get it from other vendors though. Either they use a PG that doesn't have that taste or they have figured out how to cover it up.
BTW, when i vape the straight PG, i get no TH.