Hi man ,
i know unreal is not the most easy software on earth. some easy thing came out really complex sometime.
I dont catch why you want to to this and how you want to procede once you char go 180° or make a full turn on the right.
You can easily track the amount passed out from the mouseX, Y if you use them for the rotation of the char.
Just make a variable and add the amount passed by those events (mouseXY).
They work so , for every tick , the pass you the amount of movement of the mouse.
If you dont move they pass you 0, you move slow, they pass you 0.2 , if you roll away the mouse 4 5.
When you read the value you can have any number.
If is <0, you turned left. , if is < -180 you made at least 1 full turn on the left.
If is >0 you turned right, if is >+160 you made at least a full turn on right.
Its a bit Tricky…
Lets say that you can break the rotation of your actor anytime, and get a value from Z that go from -179 to 0 to +179.
You cant count the full turn , but its usefull.
I often have to change back my project because i found that flipping all the problem upside down its more easy than solve some logic-problem. So dont be too obstinate , try also to avoid the walls on the way.