If you accessed your ETH wallet through the link, Then You're in a deep poo. You don't necessarily need to use your private key. Even using Your Keystore file or mnemonic phrase means You're probably going to get your account hacked and funds stolen. The best thing to do is never click links on the internet you know nothing about. If there was an issue on Ethereum network like majority of the Slackbot messages say, We would know about it already. I don't need a bot to dictate what I do. Same goes for everyone else.