Focus on other things, usually I focus on keeping my accuracy centered and try to get as many 320s in a row as possible, this keeps me focused on accuracy without directly stressing about accuracy, because I don't care if I get a few 200s, all I want is to get as many 320s as I can, understand that combo is irrelevant when it comes to skill in this game, getting a higher accuracy should be your priority, and the moment you stop caring is when you will start getting better combo as a result
Essentially going into a play don't go with a strict goal in mind, focus on something broad that is not difficult to hold so you don't get nervous because you're not expecting anything to begin with, when you have no expectations and just play, and the less meaning you give it the less it will affect you, giving you more control as a result