So like everyone says--stop vaping PG...or quit altogether. What exactly do you want people in a forum to tell you? You've seen a doctor, you claim no doctor knows what an extreme allergy to PG looks like, and you're feeling better after stopping. Sounds like you found your solution. If you don't have an allergy, then you're barking up the wrong tree. If you do, it makes no sense to dwell on it and make yourself more anxious.
And there have been numerous studies on the toxicity of PG since the '30's--the only cases where heart related side effects are seen is in high intravenous doses.
I'm glad you're feeling better, but I'm not sure that your anxiety is being helped here.