Milk supply

Hi mummies. My baby is 2 months old+. First 2 days he was born, I fed him formula milk as he couldnt latch on and my milk havent come out yet. 3rd day onwards, I started exclusively pumping and give him formula only if milk supply not enough. But since last month, I havent been pumping as much as I used to cos I really dont have the time. But I really really dont want my milk supply to just be gone. I still do want to feed my child breast milk. Any advice besides pump while baby is sleeping or find time? Because while baby is sleeping sometimes I'd accidentally fall asleep too or I have to use the time to shower and clean and by then I'd be very tired. The muscle spasms I'm getting on my lower back is also not helping while I'm pumping.