Definitely get all the testing done to rule out myocarditis and structural/functional issues. I am 10 months post Pfizer booster and only now starting to pull out of this a bit- seems to be autonomic nervous system stuff as all my tests are normal for structure and function. I did test positive for autoimmune markers, inflammation marker and have really high histamine levels so I take a bunch of supplements and am doing a low histamine diet. I start with a functional dr this week. I also found a return to activity protocol adapted from POTS to long covid heart reconditioning so I’m slowly rowing my way back to a mellower less flighty heart. I’m happy to talk more! It’s a non linear process though…