How to move slider from any position

Hi, dear awesome developer of the Unreal community, I have a function that I need to do but I don’t understand how to continue from my current blueprint, so I am doing a image rotation scene with using slider as a control…

I am currently using a slider to control a widgetswitcher to interacted with the picture… One thing I wanted to do is to be able to slide to a certain angle, then when I release my mouse and when I continue to touch the slider, it will continue from where it left off rather than it move back to position I touch… And when it reach the end, it will loop from the begin… Is there a way to done it?

below is a screenshot of my code