If you need EMERGENCY HELP AFTER HACKING! then a) we're very sorry and b) please let us help. It's enough to think about just ensuring that the hosting on your website has been managed in such a way that your site is backed up.
It's quite another thing restoring after that back up. Often companies don't run drills to deal with hosting crises and can find themselves in sticky situations if their site goes down. Of course it might not always be hacking, it might be an application error, an automatic patch update gone wrong or hardware failure. There might be DNS problems or domain certificate issues.
if you've been hacked, had a denial of service that's disrupted your website, or just frankly it's stopped working then come seek help.