Steam account hacked! [closed]

You did the right thing in contacting Steam support.

All you can do now is continue down the support workflow with them. Provide the Steam support team everything they ask for: Previous purchase receipts, proof of identity and so on - everything that they can use to identify you are who you say you are. Hopefully it's enough to restore your access to the account.

If and when you get the account back, I would highly recommend changing your password, adding your mobile to your account, and setting up 'Steam Guard Mobile Authentication': a 2-factor auth service for an additional layer of security. You can see instructions on how to do this here.

We can't offer any more advice than that I'm afraid.