My worst nightmare

My baby is 3 weeks old. breastfeeding has been going horribly. My nipples are severely damaged and have been since the beginning. My lactation consultant suggested taking a break and pumping only for 24-48 hours to let them heal. I went to pump and only produced half an ounce from one boob and nothing from the other. Baby had been feeding all morning prior to me pumping though. My baby literally is on the boob all day long as soon as she's off she wants right back on. She'll sleep half an hour during the day if I'm lucky. At night she'll sleep a 5-6 hour stretch and take one more solid 1-2 hour nap in the morning after she wakes up. I feel like I'm not producing enough for her so I supplemented with formula today. I feel like a failure...