QUEENS, New York — On Sunday night, March 15, I started feeling achy. By Monday night, I was achy all over. However, on Tuesday, I felt better, as I did all day Wednesday. On Thursday night, March 19, the aches returned. On Friday, I was sick: I had a fever, ached all over, was extremely lethargic, and lost my appetite. That weekend, as I collapsed on my couch, President Donald J. Trump told journalists that he thought an anti-malaria drug called hydroxychloroquine might be a promising treatment against COVID-19. “I’m not saying it will, but I think that people may...