I'm scared because price Bitcoin down, I do not know what to do with Bitcoin at this time

if you are scared of the possibility that bitcoin might drop again , so why don't you convert your bitcoin into fiat right now . actually you don't have to be scared about that because you are in an investment aren't you ? and because you're in an investment you should understand the risk of having your money in bitcoin . all you need to do is to be prepared of what will happen in the next few months and just expect the unexpected .
that's right since fluctuation is very normal with btc we dont have to worry about our investment if we believe that bitcoin will keep rising in the next few months or years but if you are only in a short term i guess better to convert your btc to fiat and assess yourself if how far you can risk your money you needed to have the courage to face the possibilities.