Cardiophobia or real problem?

I have been suffering from extreme anxiety, panic attacks for over a year now along with physical symptoms, chest pain, discomfort, left arm pain, jaw pain, etc.

I have had several ECG's, blood tests, stress test and a 24 hour monitor over the past year, all have been clear.

Nothing has been found yet the symptoms continue, recently the anxiety has been going through a hot patch, that much so I think it's going to end up killing me.

Well, last night, I was feeling anxious all night, that much so I couldn't sleep, my body is exhausted but it won't switch off.

Anyway, late on in the night/early morning I began to suffer a constant pain right in the middle of my sternum, as though someone was pushing their knee on it. The pain was constant and wouldn't shift, because I was in the zone of dropping off and being awake I am unsure how long it lasted for, I eventually woke from it and felt like the only comfort was to push deep inside the region, to get comfortable I basically layed on the bed face done with my knees up to my chest.

Looking back it has all the hallmarks of variant/prinzmetal angina. After further reading I discovered that constant stress/anxiety can cause the potentially dangerous condition. I have spoken to my GP on the phone and they clearly don't know much about the condition as they said my stress ECG was fine, this condition doesn't always show up on a stress ECG, in fact it won't usually show up on any ECG unless you're going through an episode there and then.

I am now worried I am on the verge of dropping down dead at any minute, what should I do?