You have to hold your crypto. Never sell any altcoin or BTC: you will be a loser. Yes, you will need more patience to do it, and even endurance but it is certainly worth doing it - just HODL.
Altcoins if its among top coin coins then hold it , else better to sell the coin as in coming time it will become worthless and no point holding such coins which will give you no profits . Also keep on investing during dips to average the price and make profits on your investment .