It sounds like you have had the same issues I had. I went through three trips to the er in 3 mos. 3 or 5 trips to walk in doctors. EKG's were always perfect, blood work fine, bp and pulse fine. Finally had an angiogram where they found my LAD was bridged. They put a stent in and I was fine for a while. Now I am having symptoms again(they don't seem to be the same as before). I am wondering if it isn't something GI from the meds and probably even more likely just anxiety this time. Wondering what they did to treat your bridged artery and if there were any complications after.
I would encourage you to ask your cardiologist (if you don't have one get one) to schedule a ct angiogram. If your insurance approves it, it is a very accurate test and is not invasive.
I know stress and anxiety can make the pain worse, but I would make sure by having every test to give you peace of mind.
I had a stress test, EKG, Echo, Bloodwork, Chest X-ray, Angiogram etc and all were "normal." I didn't get any answers until I had a heart cath. Every other test turned up normal, but after my third trip to the ER in a year the cardiologist scheduled the heart cath. I just happen to have a cndition called Myocardial Bridging which is rare.
Hopefully you won't have to go to that point but don't just live with the pain especially chest pain.