Ethereum

Hacked money is usually gone for good.

The most valuable thing is to:

a) Find out how it happened and what you did wrong

b) Take actions in future to prevent it

Did you have a hardware wallet that requires you to physically approve transactions on the external device before metamask submits them? If not, that would be the first step. Trezor I prefer over Ledger, because Ledger's lax security allows data leaks exposing us to scammer contacts and they had some other questionable plans.

Did you store your seed phrase somewhere secure and inaccessible to 3rd parties or internet?

Did you use a seed passphrase when setting up your wallet (13th word or 25th word) that require you to type that passphrase when doing a transaction?

These might sound like a pain, but they're really pretty easy once you've done it once and it prevents malware from executing transactions on your PC without you physical approval.