assuming the history of BTC from 2017 - 2018 will repeat this year, what you'll do with your BTC?
This depends upon the circumstances surrounding the reason on why the price of BTC dropped.
As for me personally, I would definitely purchase more BTC and HODL it for long-term. Any opportunity that makes its price lower in the market is also an opportunity for me to earn them. Another thing, I do think that people are taking for granted the technology of the blockchain and its application in the world. That is why I do think that prices of BTC will definitely skyrocket AGAIN in the upcoming future.