It's classic beginner mistake, I've been there. You could have prevented the loss even without any specific trading knowledge by using stop-limit order on your trade. Once you see you are in the positive area you put a stop-limit in the green zone and sleep calm. You must only keep in mind that if you have plenty of low volume coin you'll want to make more then one order on different levels, otherwise price might just skip your order if going down fast. And of course if it grows tighten the price-noose. Know what I'm saying?