HTC M8 T-mobile GPE conversion screw up - Hboot 3.18.0.0000 and S-ON

Hey everyone, this is my first post on xda and I'm hoping I could get some help regarding my HTC M8. A while back I attempted to convert my M8 to GPE, but alas the process was unsuccessful (at least for the most part). I don't quite remember the cause because it was several months ago, but I'm pretty sure I made a mistake and took an OTA incorrectly. After the failed attempt, my phone ended up soft-bricked and displayed nothing but a black screen. Luckily, I was somehow able to get to CWM recovery and flash Skydragon GPE 4.4.4, which at least got the phone working for the most part. Unfortunately after the whole fiasco, the M8's bootloader background became black and displayed a broken "Android" lying on it's back. To make matters worse, the bootloader was S-ON and displayed the Hboot as 3.18.0.0000 (which to my understanding is the GPE Hboot and puts me in a catch 22). The Radio and OpenDSP displayed "INVALID_VER_INFO" and the OS displayed "1.57.531.7 (2.12.1700.1)". I recently flashed TWRP and the OS became blank.

I would really appreciate some help restoring my bootloader screen to normal and/or accomplishing one of two things:

1. Upgrade my phone from 4.4.4 to 5.x.x (The only rom which has worked was Sky Dragon 5.0.1, but Wi-Fi doesn't work which I've read is because of my current firmware.)


2. Restore my M8 back to stock sense with root.

I've tried flashing GPE and Sense Firmwares/Hboots, but all failed and gave me something like "error 99" (likey because it's S-ON).
I've tried gaining S-Off through Sunshine, but Sunshine says it needs a rom or kernel closer to stock in order to work.
I've tried flashing stock roms to get Sunshine to work, but they all fail and either get stuck at HTC load screen or give "error 7" (also assuming because Hboot is GPE and not Sense).
I've tried several different versions of alternative roms that could work with Sunshine such as ARHD as well as Maximus HD, but all fail and give "error 7".
I've tried to restore to stock with several T-Mobile RUU's, but they all fail and gave me "error 159" (probably because of conflicting Hboot 3.18).

So, is there anything else I can do? Any help is greatly appreciated. Thanks!

Below is some information pulled from ADB to possibly help shed more light on the situation.

version: 0.5
version-bootloader: 3.18.0.0000
version-baseband: INVALID_VER_INFO
version-cpld: None
version-microp: None
version-main:
version-misc: PVT SHIP S-ON
serialno: FA46RWM19558
imei: 352628061928554
imei2: Not Support
meid: 00000000000000
product: m8_ul
platform: hTCBmsm8974
modelid: 0P6B13000
cidnum: T-MOB010
battery-status: good
battery-voltage: 0mV
partition-layout: Generic
security: on
build-mode: SHIP
boot-mode: FASTBOOT
commitno-bootloader: 6e0f5a3d
hbootpreupdate: 11
gencheckpt: 0