My experience is similar I was so dizzy and I would get shortness of breath , my left ear was plugged , I couldn't sleep due to my heart racing, after several doctors blamed it on anxiety found nothing wrong with all the tests and several emergencies.
I went back one more time because I knew something was really wrong. They admitted me after they finally did a full blood panel and my potassium was a 2 the doctor asked if I wanted to be resuscitated due to my heart stopping , so I spent four days in the hospital (I survived ), sense then my platelets were high Seen a hematologist I am on HU 5000 & blood thinners. I am looking into the vagus nerve which controls all of our systems {verry interesting!! I finally received an upright MRI looking at an old neck injury... I have CCI which is causing my whole body complications. I am finally finding the source after three decades. I hope they can help you. I just kept on asking the universe for help. I know am at the point now were I need to surrender to the fact that I am really sick at age 55 I am sick in tired of being sick and tired. I also know that through my experience there may be someone I can help.