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. 
Just relax dude because creating panic will not help you get profits. I suggest you to hold until it bounce back higher to your buying price. As long as you keep holding your coins you will not lose any of your funds.