I'm sorry you got bad lesson. Thankfully happened when you only had a little to be stolen. Less that 1 SBD.

It is common sense not to enter any keys anywhere. This is like giving criminal keys of your house. Besides, use your posting keys only. Even if someone get access to your posting keys, he can't get any of your funds.

And be sure you are keep powering up your coins. If you do, someone would need 13 weeks to get them all from your account. You have a lot of protection on Steemit. But you need to learn how to use it and start using it. There is a reason, why you lock your house when gone, no?

Bottom line, you gave your key to someone else. Now change your keys by using Owner key, or he will steal more from you in the future. You need to prevent him from accessing your account. if you can't, say you don't have owner key, then open new account. Safely save your keys. And only use posting key. With posting key no one can steal anything from you.

And get into habit to not post your key anywhere. When you handle your wallet, powering up, buying STEEM with SBD, use active key, not owner key. And don't let browser save it for you. You click on wrong link, and someone can steal your password. Only allow posting key to be saved in the browser.

better yet, use one browser for Steemit and another browser for regular internet browsing. be smart. You need to protect yourself. Remember we are all surrounded (on internet and in real life) with people that wants what is our. It is your job you protect yourself and use common sense.