A lot of things happened on 2017 but its not yet the best of the best but its part of the history already.
as iam a long term holder since 2013
I wonder if you are a real long term holder since 2013 and why are you even asking as a very simple thing that can be answered by your experience from the years that you've been with bitcoin.
Exactly, by the length of the OP's experience he wont supposed to be worrying about this huge dip. Another thing, if he has been holding since 2013, then he must be very rich today. Not really a big deal if I'm on his shoes lol, I know this is not the end of Bitcoin, it has already been starting to have its mass adaption. If that happens btc will land a new ATH after ATH and so on.