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.
That is the mistake a lot of people make, and I have also made it before anyway. It is always good to get out from alts when everyone is busy buying anyway, so I have learnt over the years, one way or the other, when there is a massive deep correction, they always get to drop pretty fast and once you can wait it out, that can give you an edge to buy back much lower. It is one of those things anyway, but the market always seems to recover at the end of it all one way or the other.