Hey,
It's a hard one, but guess what, happens to everyone! I know that's no consolation, but just trying to put it in to perspective. This has happened to me so many times I've lost track.
As people have previously mentioned, sell for profit in increments. Even if you set your sell orders in a few blocks (if you really want to liquidate all the asset).
At the end of the day as long as you've made a profit on your original investment, it's all good!
Good luck out there

-Knightly