Also, have you tried MSI Afterburner software? I couldn't use ASUS GPU Tweak program because of high instability and inability to OC. Use MSI and it worked very well.
after OC-ing my Palit GTX1070 dual fan my GTA V fps dropped 20 after i OC-ed incorrectly, now my 1070 is now underperforming and randomly stops
Sounds like the incorrect OC is still in effect. Try uninstalling the program you used to OC, reboot, then reinstall the program. When uninstalling, if the program asks if you want to save settings select no to remove the OC completely.
Also refer to this video by JayzTwoCents and this may help as well:
wait a new problem has arise, the graphics on games are now kinda weird somehow really not that beautiful in a way because i played beamng and started to notice that the ground isnt that smooth anymore and there was a small amount screen tearing even though v-sync was on