No rhythm during sex 😩

I'm having a big issue. My SO really wants me to take control during sex, whether that be me on top, missionary, doggy style, whatever! And I have absolutely no rhythm which ends up making it awkward when I try to move. We have been together over two years and I still have no rhythm. I'm getting really frustrated and disappointed in myself because I want to do better with my rhythm and really impress him. Any tips or advice on how to improve it or what to do?