It would be a terrible thing if the Bitcoin pattern is the same as in 2013-2015, it could be the end of 2018 is only about 4000 $ -6000 $, as I think if it might happen?
Let's look at the pattern in 2013-2015 below:

and this is the pattern from 2016 to the present:

What if it really happened, give your opinion?

That would be possible if the economy continues to be severely degraded. I think the price of the current bitcoin is not important. Let's be important about its value and its impact on the world and businesses.
If there is more and more good news about Crypto, that means the future is better and the recovery will surely happen.