Very sore nipples

Hey everyone, well my baby was born on wednesday oct 5, she is just super cute, but my nipples are killing me so bad since... u stopped breastfeeding yesterday and start pumping my milk ans supplement ut with formula, she has taken both very well. But not my hubby, he doesbt get that my nipples are almost in blood and need to wait for them to get better to start using them with the baby again. I am using a medela single electric pump, and the reason for me supplementing with formula is because my baby is always hyngry and im not making more than 1 oz every time i pump, and i pump every 2 hours. Could it be the pump? Or im doing it wrong? I dont know what to do, need to make more milk from my breast somehow.

Please need help