Hi GiddyLydia and welcome to ECF!! I doubt that it's primer that you are still inhaling. A harsh TH is dependent upon many things, the atty itself (501, 808, 901 et all), the amount of nic, PG, VG, or combination, flavorings, the way you draw the vapor in, and the ecig itself -whether it's a mod, Riva, 901 standard set up....
There are several things you can try. How are you inhaling the vapor? Try a long, slow draw, let it roll around in your mouth a little and then inhale. Or, do a long, slow draw, pull in some air into your mouth then inhale. This will cool down the vapor.
If you have plain PG, try vaping a little of this. If you get a real harsh TH, it might be the PG. I'd also try this with VG if you have any for comparison.
If it's not PG or VG related, try the nic strength. Take a 3ml bottle, fill half with your juice, then fill half with PG or VG. Now you have half strength nic. If there is no harsh TH, then it may be the nic strength.
Are you drinking water/liquid when you vape? Vaping will dry out your mouth and throat sometimes causing a harsh TH. Try drinking liquids between vaping.
It might also be the juice itself. Some vendors make juice with alcohol and/or citric acid to create a strong TH. Some people prefer a strong TH as it simulates cig smoke.
Hope some of this helps. Post back on how you're doing and if anything has helped.
