Oh God! More than half a million USD worth of Bitcoin lost. Are you sure that it was a keylogger? I am confused. How did they managed to install the keylogger in your desktop? Or are you using a computer in a public place such as library or college? It was much better to purchase a hardware wallet such as Trezor and Ledger and keep the coins in them. Anyway... don't lose heart.
Probably downloaded something suspicious to visited a website with javascript enabled. It's so easily done but so easily avoided at the same time.