Frame drop and weird distorting line?? PLEASE HELP.

[Moosh]

Hey everyone,

recently, on CS:GO and other steam games i have gone from getting a constant 250+ frames to now never getting above 80 frames...
Along with this, a weird line that scans across from the bottom to the top of the screen has appeared, and it kind of distorts every part of the screen around it...

It all started after installing Rocket League and playing some Just cause 3...

PLEASE HELP, it's really frustrating as I cant really play cs and be good because the line really messes a lot up

Leave ANY  suggestions on what this could be, and how it could be resolved, and I will be extremely grateful

Thanks

**EDIT** 1. I have found out that it's called a screen tear
                 2. I have found out that it only happens when I'm playing a game in full screen mode.
                 3. I'm no longer playing in full screen mode and I am back to hitting 1 taps