Bitcoin price fall and increase are common, every time during the fall people will be getting panic and used to sell low missing the profit. With bitcoin one need to have the patience to profit rather than selling on panic. This time the price drop is very big, but the same doesn't have a perfect reason behind as every digital coin is experiencing a drop and only very few are in the price pumping.
Don't panic when its price falling down. It is normal because as what you have said this is a type of digital coin so that the tendency is the rise and fall of it. We don't have to worry when its price goes down because there is a big profit if its price rises again. Of course, patience is very important because if you don't have it, it will lead you to a bad mood. Don't sell your bitcoin if its price was falling instead, wait again until its price goes up. It is the big impact when the price fell down. This is the big possibility for you to have a big profit. There is a great reward that awaits.
Stay brave because the fall of price is not yet the end of every dreams of bitcoin but rather an opportunity to grab. I know you already sell your holdings by the time price hits a good mark last few months ago, but the remaining bitcoin you had still there in your wallet storage; holding it for few days more. No worries about price fluctuations as it decreases for more reasons of dumpings from investors, and price will climb up higher again after that fall so you should be patience of waiting a good price in the future to reach to the top.