Mike in Cumbria makes a good point. During the past weeks, Microsoft have been rolling out a major update to Windows 10 (The 'Fall Creators update'). The update is completely automatic and the first part of the process seems to be done in the background so you wouldn't even know it was happening. During the later parts, users are asked too sit back and wait while the PC is updated and restarted a few times. If this update didn't go as planned, it could result in apparent 'data loss'. This happened to someone I do voluntary work for. Something went awry and he's basically got a 'clean PC'. His programs and data (which wasn't much) have disappeared.
Your computer could have been physically wiped clean by a hacker but it's quite possible that your data is still physically on the hard drive, just not accessible via windows (or whatever). There are IT companies that can check what's on the disc with special programs and try to restore as much as possible (for a fee). Some companies even specialise in recovering 'lost' data. I've no idea what they would charge but it's worth checking out. In the meantime - since it seems you're being targeted - I would avoid using the internet via your PC. The less it's 'interfered with', the better the chance of restoring the lost data.
I do wonder what the 'payoff' is for the hacker unless it's someone (working for someone) you know and have offended in some way. Malice could then be the reason for targeting you. Normally, hackers want something of value, either by demanding a ransom to get your data back or by collecting and selling e-mail addresses, bank details, etc. The only reasons I can think of to alert you to the intrusion by wiping your PC is either a future ransom demand or just plain malice.
However much data you're able to recover, the very first thing to do (off-line) is to make a copy to a memory stick/external drive. The second thing is (with advice from the people who recovered your data) is to beef up your on-line protection with something like Norton or Avast. Also change the passwords for your modem/router and check that the security settings are OK. Your internet provider should be able to help you do this.
The third thing to do is to completely scan your PC for 'Malware' which might have already been put there. You could also ask the IT-company who helps you recover any data to do this first. Don't forget to scan the external copy of the data too.
The last thing to do is to set up a backup schedule either to an external drive or to somewhere in the cloud (using something like backblaze). If you data is valuable and not backed up on an ancestry site, I'd recommend regular backups both to an external drive and to the cloud. Then whatever happens to one of them, you always have the other.
Mike