I know how you feel.
It seems a lot of people get (often quite severre) chest pains with GERD. I tend to have milder ones, but they just don't go away, virtually ever. My doctor reckons it's all due to acid reflux, but that doesn't stop me worrying.
I'm also rather prone to anxiety (in fact it was only after a period of debilitating anxiety I started having reflux problems) and I get this dilema all the time - on the one hand I kow I'm a healthy person in my mid 20s who's had blood tests, ECGs etc done - on the other, I get convinced on occasions that it's something more serious. Logically, that's extremely unlikely, but I know what it's like to be convinced that it is the case.