Change Character Movement Speed Relative to Character's Rotation

Hello Community!
I am making a Top Down Twin-Stick Melee/Shooter game and I am trying make, as the title suggests:
How to change the Characters Movement Speed when moving in a direction that is relative to its Rotation.
More specifically, I am trying to make the character move SLOWER when moving in the oppposite direction to its Foward Facing Vector. Demonstrated here in “ALIENATION”

This is my current rotation system, which was taken from the Twin Stick Shooter tutorial produced by Unreal:

Ive been tackling this for a couple of days now, and would really appreciate some directions or Blueprint Examples!
Thankyou in advance!