Camera problem in rolling ball game with custom gravity direction (gimbal lock?)

So, I’ve been working on creating a rolling ball game with a dynamic gravity system and have run into a problem.

I trace to the ground to get the angle of the floor the pawn is on and with “make rotation from axes” create a new rotation for the camera so that the new ground is the new “down” direction. The problem is now that if I try to move the camera it moves relative to the world and not relative to the new plane.

Here’s a small video to illustrate the problem:
And here’s my blueprint: Imgur: The magic of the Internet

I guess what I am looking for is a camera control scheme that moves the camera relative to a custom plane, but I can’t get it to work.
I tried implementing this:


but it didnt work.