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.
I hope that everything now does not begin to panic and sell all the coins. Typically, most dumps are due to FUD