Red and Green Rectangles

Basically what is going on is that these green and red rectangles appear over anything I put my mouse over. My fps drop and everything slows. When I don't have my mouse over anything my fps jump back up to normal. I have been forced to play support since last hitting is near impossible with this bug. And by everything I mean these boxes appear over minions, monsters, towers, nexus, inhibs, champions, anything you can interact with. Please help!!