Only pumping out 1oz 😩😭

I would really appreciate it if anyone could give me some tips. This is my first time breastfeeding and I’m getting frustrated. All I pump out is 1 oz.

when baby boy was born I gave him boobs only at the hospital. Once I got home, i had to get formula because my nipple were so sore, I couldn’t take the pain. I’m switching back and forth with breastfeeding and giving him formula. I feel like he doesn’t get full with my milk. I purchased the Haakka pump and I put it on whenever I’m feeding him on the other boob. I also have the Medela pump. Whenever he’s asleep I pump for about 15-20 minutes but all I ever get is 1oz. But I don’t pump everyday since I’ve been staying at my moms house since I’ve had my son and I don’t have much privacy. Is there anyway I can increase my milk supply? I really want to stop formula.