Left joystick does what he wants?

My ps4 controller has been causing problems for about a week! My left joystick performs the command "up" irregularly, although I do not push up! If he just lies around he does not do anything but as soon as I play and move him and, for example, press down, he pushes up. Have it already resetet and blown through the joystick from the outside and game and console restarted everything without success what should I do?

He is probably broken.

1. You are buying a new one

2. You fix it which only costs time, money and nerves.