[Req] Translating Yaw/Pitch/Roll from MPU6050 for FreePIE

[ElectricPotato]

No idea if something like this is suppossed to go in the Requests here, but I'm at my wits end and my skills with math and code are nowhere NEAR what I need to complete this.

Basically, I've been building myself a VR Headset for use in SteamVR. I got almost everything working correctly, from Controllers to Rotation and Position Tracking, and it all works really well!

However, there's one small problem. One final little piece of the puzzle that's gotten me stumped, as it will likely require an entire do-over of everything I've done so far.
Roll tracking.
My problem is this: When I look in any direction except directly forward, the other rotations (mostly roll) will screw up. As in, when I look left and then roll my head it'll twist confusingly.
I don't know what the problem is exactly, and any answers I've gotten have boggled my mind with talk of Quaternation and Euler Angles - I don't like to admit it, but I'm WAY out of my field as far as this goes.


So, my last hope for this: Is there anyone out there who is able, and willing, to remake my current code using the correct math to calculate yaw, pitch and roll, and output them to FreeTrack like the script currently does?

I'll upload everything I've currently got: the Arduino .ino (which I got from another project and re-used for myself), and my FreePIE script minus Positional Tracking stuff. Pos. tracking isn't necessary to fix - it works flawlessly - and it'll be easier to see everything without it cluttering up the script.

[ElectricPotato]

If anyone sees this, never mind.
For one Thing I roll my head a lot less than I thought I would, and for another I broke my screen yesterday so I can't use my headset at all now.
Hooray for my incompetence!