Ok, hello everybody, i actually don’t know if this will be useful to anybody because i seems to be the only one with this problem… But i want to share the solution i actually found.
Lately, overwatch had some severe freezes. And i talk about the game stopping moving for 2 to 3 seconds then coming back up, which was severely handicapping. Yesterday it got to the point where the freeze got so severe that the game never was “unfrozen”, i had to shutdown the game via task manager and lose 50 SR. I accepted it, it was my fault.
But i decided i couldn’t take it anymore and to dive into the problem. I discovered those freezes actually happened in only 2 of my games : Overwatch and Osu… So i quickly ruled it out of being an overwatch related problem since osu have nothing to do with blizzard.
I tried games like Dead space, Rainbow Six siege, FF13 or 14, various PS2 emulators with different games (that are demanding on the gpu) and no freezes.
After a lot of trial and error, i finally narrowed it down, and it is the geforce experience overlay, clear and simple. The overlay is activated in only 2 games for me, which are… Overwatch and Osu, yep you guessed it right.
So what i suggest if you got the same freezes as me is actually to go to geforce experience, click the cogwheel and search for a button called “share” and uncheck it. Normally, all your freezing problems should be gone.
I know the technical-support is usually to tell what problems we have, but i feel like i’m probably not the only one having this problem. From what i’ve seen, it’s mostly people with a geforce gtx 1060 that face this problem but it can happen to any nvidia gpu.
so yeah, if you got freezes ? Try this fix, it worked for me and i can now enjoy a seamless overwatch experience 
Have a good day !