I’ve experienced something similar. I do have some actual diagnosed medical conditions, that are confirmed with labs, tests, etc.,but also have other issues that aren’t as easily diagnosed. It can be scary and stressful. It’s good you are addressing this now.

Do you derive any satisfaction that all the tests, including the heart monitor shows no physical problem? And that the cardiologist says there is no problem? Would a second or third opinion put you at ease? Do the tests at medical facilities reflect a high heart rate? Have you calibrated your bp monitor? What do your family members say about your symptoms?

I have found that a combination of things have helped my health anxiety including talk therapy, daily exercise and good diet. My therapist helps give me tools to help me with an internal dialogue as I encounter ailments and how to properly evaluate them.

I have a couple of family members who have extensive medical records with ER visits that goes back for many years and the only culprit was anxiety. It’s not uncommon.