Then instead of it being physics based, you may just want to use an animation montage, and then the montage moves in the direction of the character’s most recent forward vector. While the character slides, you can DISABLE_INPUT.
And, you are mixing up PLANE with AXIS. You want the character to slide along a single plane, but, again, that character will be moving through two axes. This is an important distinction because if you go with the mindset that you are only using ONE of the COORDINATE values, your results will be inconsistent.