if your cpu is at 100% there's a bottleneck
altho this also can be caused by a lot of background programs running (AV, onedrive, origin, steam, uplay, ....)
try first to disable as much unneeded startup programs
reboot
and start your game
if it's still at 100% you have a CPU bottleneck
if you would have overclocked bad your device would crash so i presume you did a good job