...20 or more coins are okay but you need to watch them carefully for profit booking. I once held much bigger amount of altcoins but those were from bounty hunting and from other reward systems. So, how many coins you hold is not a criteria until you are able to track them and manage them.
It looks like the OP bought his coins when the market was high, and now, if he didn't sell them, he must have a very large loss, which reaches about 50% of the initial deposit price. If he had been holding BTC, this loss would have been half as much.