Converted D800 to D801 and can`t revert back.How to fix?

I flashed a T-Mobile Kit Kat 20g based rom on my D800 and got a lot of problems and can`t flash back to stock AT&T Kit Kat rom.The problems I`m having with the Kit Kat rom is no Play Store,no internet, and brightness don`t work.I tried tots method and that don`t work.It appears that my D800 is now a D801 with no way to return.If anybody got a fix let me know.

Also I have to reboot several times to get the usb to work to transfer files.