Please make sure your E-mail is secure, that there are no keyloggers or other malware on your computer, and then change your password using https://en.nostalrius.org/password . Make sure your password is different from that used on other private servers.
We cannot return stolen items to you, but we are tracking down the perpetrators. All gold obtained from these hacked accounts is traced, so anyone who purchases gold from these gold sellers will be banned.
Note that it seems like your account is not banned from your description. We advise you secure it ASAP as continued compromise can result in a ban, especially if the hacker takes actions on it that lead to a ban (like advertising for gold selling sites).