The Client is so laggy

Every other time i go into champ select and it's time to ban a champ the freaking counter starts going down while everything else freezes and then after clicking blitz in a panic and just mashing the ban button hoping that it actually goes through for once. It proceeds to give me an error saying something along the lines of "sorry your pick was unable to be locked in" then it kicks me out of champ select and puts me in a low priority Q.