So I wanted to get some better fps on GTA V and had a GTX 980 I had yet to overclock. So I opened GPU tweak and GTA V and slowly began to crank up the GPU Boost clock and the Memory clock. Now everything was going fine, I usually get ~60 FPS on GTA V, so I changed MSAA from 4X to 8X and that is when I started changing things. After a couple adjustments I got 10 frames more than usual with 8X. So on the final adjustment, GTA V crashed so I could still hear the in game sound but the visual was a black screen. I closed GTA V and restarted it and changed back to 4X and put the GPU clock to default. And got around 25 frames when I got in, and this was just in the house where I usually get a solid 60. I checked the files on the game, it replaced 1 but still did the same thing. So I opened BF4 and even though I had over 30 it still halved what I usually get. I would really appreciate some help and hopefully I haven't screwed myself. Specs are i5-6600k, GTX 980, EVGA 750W PSU, and windows 10.