why is my magic mouse suddenly doing things i don't want it to do? zooming in and out without even touching it? stopped scrolling & swiping and when clicking brings up a sub menu?

hi hope somebody can help me before i launch this thing at the wall!!! i have had no problems with my imac before but all of a sudden my mouse has taken on a life of its own.

its zooming in and out side to side all over the place when i'm not even touching it. yet when i want it to zoom in and out now it dosnt even acknowledge my tapping and swiping. (its actually zooming in and out as i'm writing this!!!!!

when i click on anything instead of doing what i want it do do it brings up a sub menu?

i have a feeling when my baby smacked the keyboard, it may have something to do with it but i have since gone into the mouse settings and made sure all the boxes are ticked etc.. has he broken my mac? :/