Not that anyone cares lol, but I figured I would update this post incase someone searches this in the future.
I ended up trying out the cheapest and easiest part to replace, bascially throwing parts at it, and bam it worked. My factory trailer brake controller was the problem. I had one sent via Amazon, $43 later changed it out and works like new. No more stupid computer telling me to service trailer brake system. I love my GMC's, but kinda crazy the factory brake controller went bad on a 3 year old truck with 57k miles. O well, could be worse