|"Can I just create a new user with my old deleted user name and have everything back to normal?"|
I am sure by now you have tried this and discovered that the answer is no. Real serious message when deleting an account of unique sid and unrecoverable.
You can create a new user and copy the contents of settings and documents to that profile.
But first you have to change the local policy to allow interactive logons.
Imagine the power if you knew how to internet search