I think bitcoin could well reach $2,000 - $3,000 if this $6,000 support get's broken. If you would sell now chances are high you could buy back and thus double your btc holding.
This is not financial advice, just a thought.
And this is not a good year for crypto I believe. Late 2019 we'll see some action.
I think your analysis is too risky, selling at a cheaper price is more likely to lose, I think more to hold and just sell it when the price is high again.