The crash may have been caused by the Korean exchange hack,creating some FUD as regard security .not likely to fall below 6k..will likely recover sooner than you think
I do not know what was the reason for the crash but I am sure: very soon, the price of Bitcoin and the other cryptocurrencies will start to go up. It will be a very long process, and I believe that it will start before the end of 2018.
What pushes you to believe that ? I personnally don't see a bull market coming anytime soon or even this year, but maybe I'm just being pessismistic.
Hopefully you're right and we will pump back up there by then end of the year.