Hello. Almost all of us here have something like the same history, mostly with symptoms and how awful they are, and with the accompanying anxiety. You might be surprised to learn that some of us have no symptoms, and little or no anxiety. Them's the breaks!
You won't die from ectopy. Period. You may live truly miserably, wretchedly, due to the extent of your symptoms. But the ectopy won't be the cause of your end. Worry might.
I would recommend a double approach of CBT (cognitive behavioral therapy) and consulting an electrophysiologist (EP). Between those two, a good therapist and a good heart electrician, you will find some relief. It seems your GP is not going to bat for you. Sorry, but this is what I sense from what you have said.