Funny I had a similar experience, late twenties, felt completely healthy, but was constantly having chest pains. I was a bit over weight at the time but I walked everywhere and was really active, doctors office my BP was always ~ 140/80, he prescribed me meds but I wasn't satisfied with that. I went and got a full heart study done and a 24hr blood pressure monitoring done, my heart and BP are totally fine apparently.

I really freak out about getting my blood pressure taken in a clinical setting, it's really unusual.

I had some treatment for a kidney stone recently, and after the procedure they were checking me with some pretty accurate machines, like 10 times in 24 hours (apparently), 128/80, for some reason in that specific setting I didn't freak out.

White coat HT is a weird thing.