mobile

First off here are the current details of my device:

-------------------------------------------------------------

Model Number: SAMSUNG-SM-N900A
Android Version: 5.0
Baseband Version: N900AUCUEOC1
Kernel Version: 3.4.0-4335446
Build Number: LRX21V.N900AUCUEOC1
Knox Version: 2.3

-------------------------------------------------------------
(Sorry I would have posted screenshots but I don't have 10 posts yet.)

I bought the phone with KitKat 4.4.2 and Baseband Version N900AUCUCNC2
Since then it has been updated through:
KitKat 4.4.4 - Baseband: N900AUCUDNJ5
KitKat 4.4.4 - Baseband: N900AUCUDNL1
and now Lollipop 5.0 - Baseband: N900AUCUEOC1

I carelessly updated my phone via Firmware Over the Air (FOTO) not knowing at the time that it would change the process for rooting the phone later on.
I have tried many tutorials and checked various threads throughout the forum for a solution but it just seems AT&T phones are extremely hard to root nowadays.

Some of the things I have tried without success are:

TowelRoot
KingoRoot
Root De La Vega
and possibly a few various other methods.

It is also possible that I may have done one of the above methods incorrectly, although I tried to follow the instructions as carefully as I could for each tutorial.

I have heard that it is easiest to root this phone while it is at KitKat 4.4.2 and I am curious if there is a way where I could downgrade the Android version and successfully root this phone. But I have also heard that AT&T patched 4.4.2 so that it was harder to root although I am not quite sure if this matters.

If anyone has any solution to my problem I would so greatly appreciate it. I want to be able to use this phone to its full potential before I get a new one. :)