Its not bad to sell your holdings after all because that's what we called cut loss but if you think this dump is just temporary then better not to make any action or just keep on investing. We can't say when the market rise high again but you have to make yourself more confident about cryptocurrency, this is our future that's for sure.
Cutting your losses is only the right thing if the coins you bought are terrible and you do not think the coins are going to recover, but if you bought coins like bitcoin or ethereum there is no point in selling your coins, keep them it is not going to be easy but if you do you will get your reward when the price recovers because the majority of persons which bought their coins in the last months are not holding their coins anymore.