I think for the yo-yo to stop, you have to hold on to the yo-yo when it is up in your hand; it is only then that you can take it off your finger and put it away.

As frightening and painful as the yo-yo is, it's still attached to your finger; you cannot deny that; if you let go it just drops down and bounced around a bit and gets in your way and you trip over it. I think you have to look at the yo-yo and realized that though attached, it is not part of you and can be unhooked and let go of so you can do other things. But yes, you have to look at it first; attend to it and how it "works", hold it completely but lightly so you can loosen the string around your finger.