How to change a flipbook depending on direction enemy is facing?

Hi

I am doing a RPG using 2d sprites in a 3d world. The problem im having is changing the flip book for an enemy when it is moving up, down, left and right… Also need to lock movement to the x or y axis not both at the same time (4 directional movement) please can somebody help?

Many Thanks

I have the sprite turning left and right now using the attached bp but cant get it facing forward and backward… PLEASE HELP???