I bought 3 btc on credit for 19k about. What should I do? I am way underwater.
You don't have any choice, you already lose a lot so maybe it is better to just hold until bitcoin will recover more and hit another ATH's this year. Having a patience can make you profitable in a long run.
Yeah, if you sell it right now, you have to bear a heavy loss as the price is still about 8500$, leaving no other choice for you other than holding it. However, I believe the price will soon uptrend and achieve new ATH this year. But for that, you have to keep faith in it and hold it for as long as you could...