Help! Lost My Bitcoin Wallet

I lost my bitcoin wallet. Got the key, but the wallet itself was saved on an external hard drive. It got stolen... What can I do to get it back? Also, if someone has bitcoin and a wallet address but lost the actual wallet, can they still retrieve it?

What kind of key do you have? You need the seed phrase or private key. Anyone can know the address, but they can't use it without the right key.

I have the private key... but no public address or the wallet itself since that hard drive is gone.

Download Electrum. Create a new wallet there. Write down the 12 recovery words. Then under Wallet/Private keys, use the Sweep option with your private key.

Just keep in mind that sweeping means you'll create a new transaction and pay miner fees. So it's super important to keep that seed phrase safe. If you want to restore your old wallet instead, just use the 'use public or private keys' option in Electrum.

That wallet is gone for sure. Sweeping it is your best shot now.

If you misplaced the hard drive with the wallet file, you might be in real trouble losing those bitcoins. I bet you actually know the addresses in that wallet with your funds. Check those on a Bitcoin block explorer. If the balance is zero, well... you’ve lost it. If not, act fast to recover it before anything else happens.

I really hope you didn't keep your keys on that hard drive. If the thief knows what they're looking for, you need to create a new wallet ASAP. Since you have the keys, you can move it to a safer address. Had a similar issue before when my hard drive disappeared back then, I stupidly stored my keys on it too.