I may be wrong but I suspect that even now, your positions if sold now would produce fantastic profit......albeit much less than when you sold your “sliver” in December.  No one knows where this will go or when. How do you know that the price of BTC won’t tank by another 75%.? 
Maybe you should sell 25 % now.  
In the 1990s I sold Nortel at 120. I sold 50% of what was left at 45 . I sold the last bit at 8 . All three of those decisions where good ones. It went to zero.