Windows 10 update 1803 renamed the user account folder with .000 suffix
I think you was using a Microsoft account to login, then upgrade system to 1803 version.
Try to roll back to the previous Windows version.
Sign-in your PC with a local account.
Upgrade again under the local account.
Note, don’t use built-in Administrator account as local account.
Reference:
Why user profile is C:\Users\ username_000 (truncated username and underscore)
https://social.technet.microsoft.com/Forums/ie/en-US/37c266c0-0124-4fb1-83b7-8bde4db986b0/why-user-profile-is-cusers-username000-truncated-username-and-underscore?forum=w8itprogeneral