Upgraded GPU to RX 570 but performance is worse on all fronts
So my Radeon R7 370 died last week and I replaced it with a Radeon RX 570. After a day of dealing with error 192 while installing adrenaline, somehow the drivers magically installed by installing the Radeon software itself and now it says up to date!
However, when I try to play my games, Overwatch and Farcry5 I am getting horrible screen tearing, and lots of overall jitter. I have tried lowering the graphics settings, triple buffering, Vsync, frame rate caps, locking the refresh rate to 60hz (for my monitor). each of these options presents another set of problems though. Turning on Vsnyc almost gets rid of the screen tearing, but then I am getting random moments of game lag/freezing and input lag. Lowering the graphics settings does not fix the screen tearing, or the random freezing.
One important difference in my setup is that with my previous card I was plugging my monitor into the DVI port with a DVI to VGA adaptor, and now I am using a Displayport to VGA adaptor, maybe this is an issue?
I am wondering why my performance could be so much worse, is my CPU underpowered?
Is my monitor the wrong refresh rate (why would it work on my old card but not my new?) ?
Maybe another component is faulty besides my gpu?
Thank you for any help, I have 25 days left to return the RX 570 and maybe get a card that will work, so time is of the essence.