Sorry, I'd be simply researching the problem. Needs someone who's been there and done it. I can't understand how you can be in such a predicament.. so hope someone else can offer advice.
These threads are relevant:
Solved Windows 10 no administrator access - Windows 10 Forums
Solved I lost all of my administrator rights when I downloaded Windows 10 - Windows 10 Forums
No Administrator Account After Win 10 Novermber 2015 Upgrade - Windows 10 Forums
Lost full control of computer since upgrading to windows 10, no admin - Windows 10 Forums
The only relevant tutorial here is:
Administrator account - Enable or Disable in Windows 10 - Windows 10 Forums