I would not sell just yet. I expect the price to rise back up to over $4000, probably $5000 again in the next six months. At this point, I see a large drop to be very unlikely in the next few months. That being said, there is still a ton of uncertainty with cryptocurrencies, and banks and governments will almost certainly try to shut them down at some point. Whether or not they will be successful in that is anyone's guess. With all the advantages of cryptocurrencies, I can't really see them dying out completely, but there could be a huge drawback at some point when large first world countries ban them.
All that being said, one in the hand is worth two in the bush. You ARE up significantly at this point even with the drop. Only you can decide what risk you are willing to take.