I suggest you Hold on!
Although the price is now falling, you bought three BTC for $19,000.
The price is now $6,600, and your 3 BTC is not getting any less!
The price will return to $19,000! Maybe more!
If you sell now, you'll regret it!
Well i think there is no other choice than to hold or else you will loss a huge amount .Maybe it is really a verry hard thing to do specially when you always see the price that slowly dropping down almost everyday it is really killing those who invest in the high price to see the present price fall.I think we must believe in bitcoin and it's capability to rise again to avoid stress.
This is what over excitement brings. I can bet that he bought bitcoin without doing any research about it. If he had, definitely things would have been different for him. He would have known that bitcoin falls down during holidays and on big events, a pump can be seen.
Also he would know that after every decline, it recovers and when that happens, a new record is set. Sooner or later, bitcoin is going to touch 30k dollars this year. A little faith and patience is all that is required.