this is a precious experience for you right here.
next time don't bag hold altcoins taht are in a bubble and will get dumped hard as soon as the whales find an opportunity to exit. try and look for coins that have been getting pumped and invest in those instead of mindlessly holding on tight to certain "names" that are big.
The whales are getting into pretty much any coins that's out there. It's impossible to know which coins are going to skip having whales jump on.
Diversification of the portofolio is the solution. And right now it's natural for the market to go down.