arms twitch when aiming. pls help

whenever i aim in whatever game im playing and i take the shot my arm randomly twitches almost as my boy makes me do a flick shot while my crosshair is already on the target. after some research, i think its a nervous tick caused by anxiety, ive never really experienced anxiety before so it kinda confuses me tho. if anyone has had this problem before and was able to fix it please tell me hoe as its really starting to screw with my performance