I'm sorry things have been so bad for you. I hope things get better.

AFAICT, the antibody tests for people who no longer have covid-19, but might have had it, range from unreliable to useless. They may be good enough for demographic estimates, but that seems to be all.

February is early to have caught it, but it seems as if the more people research, the more cases there are believed to have been, at earlier times. Depending where you are living these days, you could reasonably have been one of those cases.

Have a virtual hug from afar, if you want one.