During the last week I bought coins and they almost immediately fell by 10-15%, and today early in the morning I saw how they fell by another 15-20%. How long will it last?., and whether I should sell for what I have. I wouldn't want to be left with empty pockets. 
Apparently you entered the market at the wrong time, but do not be sad so quickly because many now have higher drawdowns on the coins. If you're new, I suggest you hold the coins and don't sell them right now. Better be patient till the end of the month. In any case, this is a high-risk market and you decide when to sell.