Lagging with New Graphics Card and PSU?

[FireClocks]

I got a new graphics card a few days ago since my other one fried, as well as a new psu because before I had a cx600 and some experts told me I should replace it.
So now I have a GTX 1060 3gb with a cpu i5 6500k and a Super Flower (something like that) 650w.
I remember playing Overwatch yesterday and it was running smoothly around 200 and something fps, but today I went to play and it started constantly lagging, Its smooth and then lag, smooth and then lag. It's so weird I dunno why this is happening.
I have some performance indicators when the game is running that were saying the "VRAM" something like that was like 955, is that too high? Am I running out of memory O.O?
I think my disk usage goes to 99% very easly too.
And what's the normal temp for the cpu to be while I'm playing? I think the max I saw was like 75
Any help would be awesome. I don't wanna replace the card once again and wait weeks.
Could this be because I assembled the components wrong in the computer?

 

[Sedivy]

Open your task manager when this is happening. Then go under Performance, and on the bottom hit on Open Resource Monitor. Once it's open, click on disk and then check what processes are listed under "disk activity" once you sort for total B/s. Could be some sort of issue with your ssd. Could be something with windows. Could have picked up some virus or malware etc. That high disk usage could mean low memory and you're running out of space on your ssd or some process that shouldn't be there. Just double check what's using up so much disk time.