Nursing vs pumping

Does anyone have any tips on how to pump more milk? When I nurse my little one he’s satisfied, and is eating about every two hours during the day and doing anywhere from 4-7 hours at night in between feedings so I know I’m making enough milk for him, but lately I’ve been having to supplement him with a bottle of formula at night which he’s eating 6oz every time yet I can only pump 2-3 oz max at a time, and I’ve gone back to work on the weekends so I’ve been power pumping every night for a week and a half now but I’m not seeing any improvements with pumping 😩