I had a tough time with my D7200 when I first got the Nikon 200-500 lens. With the help of several on this forum, I realized practice was a big part of getting clarity, but also I needed some better settings.
I was shooting Birds on feeders and I was using multipoint focus and too low a shutter speed. What ended up happening is the wrong point was out of focus. With the help of others here I went to single point using back button focus at about 1600 shutter and AutoISO and 5.6-7.1 Aperture and lots of practice. Eventually, my shots got sharper. I also found that I really needed the tripod to steady my shots. Once I did that I could make other adjustments to get sports shots etc.
I have found now that I still do best with the single point and Back Button Focus, but I do sometimes use 9 points. I can also use my monopod, but handheld for me is very difficult. Many can do it, but it takes a lot of practice. A little motion at the body translates to a lot out at the far end of that lens.
Do not give up on the lens. It is great, but it does take some getting used too.