Trading is also a mind game you should be wiser, avoid checking coins during dumps because it will affect you emotionally and mentally. Just hold and wait else you might end up loosing your money because you are over powered by your emotion.
The way most people have been able to conquer moments like this is to avoid looking at the charts. As long as what you are holding is a good coin, there is really nothing to worry about and the coin will definitely come back speeding to the moon after a while.
The only difference is that you cannot have it all most especially for altcoins, which is why most people just prefer to stick with bitcoin and only make use of the huge dips to buy a lot of altcoins.