Most people do the same mistake. When the price of particular crypto goes down, they sell it immediatly. But it's not how crypto works.
Crypto currency value is very volatile, but you won't lose/gain any money until you sell them. That's the secret, if the value of your crypto goes down even a lot, don't sell it, keep it. There is a very high possibility that it will rise again, even for coins that are less popular.
But the brand new coins are totaly different. They are too risky but at the same time very profitable. If you take the risk to invest in new crypto currency be careful, a lot of them are only pump/dump.