Covid triggers an huge inflammatory response in many people . that can cause all kind of issues system wide including with your heart.

While its great to share notes and information , public forums and social media isnt the best place to get that information or treatment ideas and your health care team should be the first place you go for this, especially at 19.
As for me, I am a nurse, tend not to let anything slow me down, but boy this did it. I had Covid 2x, severe both times.
I had Myocarditis off and on mostly on for most of 18 mos , was on and off steroids and limited in most of what I could do physically as a result.

I am now on Hydroxychloroquine no steroids, and while I have no proof that was what finally helped resolve a lot of the post Covid issues , it sure seems like it was.

I do not have underlying autoimmune issues and they have even looked to see if they missed something.

So for now I will stay on it and also a beta blocker to help regulate the heart rhythm, but things are improving.
Everyone is different and there is a great deal they still do not understand about all of this.

Hang in there and advocate for what you need.