New
#1
It looks like you have done two things, the first was to enable the built-in Administrator account (that's the account named Administrator.) The second was to change your own account from an administrator to a standard user.
To fix this you need to sign in as Administrator and set your own account back to being an administrator.
Great! You're lucky you had the built-in Administrator already enabled, otherwise it would have been much more complicated to fix :)
What I normally recommend is that you make a second local administrator account for maintenance/repairs like this. Then you can disable the Administrator. It's disabled by default because it isn't restricted by UAC, it's safer to use a normal admin account.