The GTX 560 SE is an underclocked card meant for low power consumption. Additionally, it has 1GB of VRAM, which is a problem in Watchdogs.
You may still be getting lower performance than you're supposed to, but don't expect a miracle.
Also, as emdea22 said, you need to post the rest of your components.
specs are i5 3330 8gb ram and the video card is overclocked to 1.5
You mean 1.5Ghz!?
Take a temperature reading after an hour of stress testing on that video card. If you've really overclocked it that high it's probably damaging itself or throttling itself down from the heat.