Never sell something less than the price of when you bought it. Just how scared are you to panic sell when you see that a dump is going on. It's totally normal and times like those require no action at all. You should consider yourself as an investor, not just a trader. You are here for the long term. No one has made tons of money in just a couple of days in trading. Well, maybe there are, but that doesn't mean that it will happen to you as well.
Patience is the key. Only sell at a lower price when you thought of better investments and you want to pull out your money to prevent even more losses.