Severe Chestpains and fainting

I am a 51 year old woman who is fit and healthy, low cholesterol, low fat diet, no food before bedtime, low to average BP and pulse. Grandfather died of heart attack at 53 the other at 73, father died early of trauma, grandmothers died of heart disease in 80s & 90s. Have Raynauds, GERD nexium 40mg daily. long history of fits, faints & funny turns, usually every 2-5 years. rarely witnessed, often found myself on floor awaking from unconscious state with injuries. 3 events over past few years = woken by chest pain in the night, midway between nipple & sternum & ascending. rapid escalation to extreme pain, collapse without warning. rapid recovery, no vague state, nausea, epigastric pain, incontinence. witness said no jerking or twitching. In ED ECG poor R wave progression, no elevated heart enzymes only normal muscle enzymes, normal echocardigram. neuro assessment normal. What could it be? Previously Drs thought it was reflux with vasovagal but I have no residual reflux symptoms after event. My diet & medication should make this a low risk. I have injured my back , neck and front teeth in the recent events. I need a diagnosis and cure. Given the time of year I can’t get to see a cardiologist as an outpatient for ages. What preventative steps can I take? what questions and test should I ask for? I haven’t had a stress test or angiogram. thanks for your help.