If you haven't already sold your ALTs simply hold if your project is decent. If the project has no future sell and buy into a decent project. This is all you can do to recover your loss without putting in more money. It will probably take a couple of years to recover your loss!
Some ALTs will never recover from this crash!
It is an ugly situation!
I personally always invest in popular altcoin, because I don't want to take a big risk by investing in a new altcoin, so I will definitely invest with altcoin in the top 100 coinmarketcap, because altcoin prices in the top 100 coinmarketcap will definitely increase and of course it will give me a lot of profit than I invested in a new altcoin (not yet popular) and I always hold altcoin that I invested until I made a profit.