[Q] Update Issue after downgrade topic

Let me pre-apologize because this has probably been asked a million times already but I haven't been able to find it.
Here's the quick rundown:
I towel rooted my AT&T galaxy S5
Afterwards it failed to complete any upgrades
This led me to think the same thing will happen when lollipop rolls out
I followed the unroot/downgrade guide posted by shortydoggg
This changed my firmware to an earlier version than what I had
I now get the update notices but the update won't complete
Instead of failing at 25% when I had towelroot, it now fails at 32%
I saw a post about the bootloader being incorrect but I haven't seen a solution yet

Big question? How do I resolve this where I will be able to receive the newest updates?