Greetings Taylojos Welcome to the Heart Disorder Healthboards!
My sympathies. Something I might test for because of the brain fog and chest tightness is the Candida Albicans. This can be done with a Candida Albicans blood antibody titre. Candida Albicans might be implicated to some extent in chronic fatigue syndrome and fibromyalgia which causes muscle pain.
It did sound in the beginning of the post like heart valve damage but an echocardiogram I thought would have ruled that out. Perhaps I am mistaken. Weight lifting does often damage young men's heart valves at an early age so in my opinion it might be better to do daily walks.
I would avoid refined added sugar like the plague since it can cause anxiety, clog the system, feed candida, and cause panic attacks.