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. 
Better hold it rather than selling below the buying price, just leave it in your portfolio and forget for some time, and do something else rather than crypto it Will just give heartaches if you open it.