You did not lose all your investment. Your Bitcoin remains the same and when the price will start moving on the opposite direction, you will see how strong it remains despite the previous dumps it has gone through. Bitcoin is still alive and kicking and this dumping is a good indication that it is still alive and reacting to the market trends. Just trust Bitcoin, continue hodling, and everything will fall to its proper place at the proper time. You will be rewarded for such trust for sure.