How can I make it so I can rotate a sphere component in all directions?

So as part of a game design summer camp, me and a few teammates are making a sidescroller (not 2D) that has a grappling hook as the main mechanic. After a lot of time and searching through many tutorials, I finally got it so I could aim the grappling hook with the mouse, by using an invisible sphere around the player to aim. I figured out how to do that from this post: Rotating an object towards the mouse - Programming & Scripting - Unreal Engine Forums

However, there is one tiny inconvenience; I cannot rotate the sphere all the way around my character, because it stops just above him and then stays facing forward. This isn’t an enormous problem, but if it’s fixable, i’d like to fix it, since it’d feel even better to control than it already does. Here’s some images of my code (Pretty much exactly the same as the post linked above):

I’m pretty sure I know what the problem is; No negative numbers are being input, so therefore, no aiming behind the character. However, I don’t know how to fix the problem. If it’s not a problem that can be solved, it’s not the end of the world, but help is appreciated!

Note: I understand next to nothing about all the math going on in the first picture. I don’t know why it’s necessary or why it makes the whole aiming thing work the way I want it to. If there’s a blatantly obvious solution in there, I haven’t seen it / cannot see it.