Low GPU usage Low fps

I recently got a 1080ti for my build expecting crazy fps but i am getting low fps, on overwatch it is using 15% gpu in fights and 10% in spawn. I don’t know what to do at this point please help. My specs are - Gigabyte 1080ti 11Gb, 16gb G.SKILL Ripjaws ddr4 ram, ryzen 5 1400 overclocked to 3.8ghz, coirsair 750w, Gigabyte ab350 motherboard, 1tb seta berracuda hard drive

I assume that your drivers are up to date.
How many fps do you get?
What are your graphic settings in the game?
Have you tried to lower your graphic settings quality and see if you get higher fps? That would also help to know if the issue is related to the gpu or if you are cpu bottlenecked…
What was your previous gpu and how many fps did you get with it?
Have you monitored your temps to be sure that nothing is throttling?