Please help - is it too late for me?

My son will be 5 weeks old tomorrow. I had gestational diabetes and when he was born he had issues with low sugar. We tried breastfeeding immediately but he wasn't getting anything (I had a c section). They took him to the NICU and gave him sugar water through an IV and weaned him off until he could stabilize his sugar on his own. We would visit every 2 hours to breastfeed but he wasn't getting enough if anything and he couldn't stabilize his sugar so we had to supplement. We still put him to the breast first at every feeding and and I would pump after every feeding but never got more than a few drops. After 3 days of supplementing he could stabilize his own sugar and we were able to go home. I continued to offer the breast (with a nipple shield), give him formula, and then pump. I didn't start pumping much until day 8 PP and then I was only getting about 8 ounces the entire day. I would usually get 3 in the morning and then one or two ounces through out the day. Eventually I gave up. My nipples were KILLING me from pumping and He would scream and push away. I'm not sure if he didn't like the nipple shield. It was hard seeing him push me away and he just wanted to eat. I never engorged at any point even after I stopped pumping.