Help!!!!

My baby is a preemie and is 3 weeks old (32 weeks ) I’ve been pumping but I barely get any milk . On a good day I can get 20 mls . Today my nipples felt they were on fire and while pumping I noticed bright red blood ! I’m in so much pain ! My right nipple is cracked , how do you still pump through this ?? I don’t even think this is going to work , I feel like just quitting with pumping. Everyone says just keep pumping but I’m in so much pain, how are my nipples going to heal if I just keep pumping and it just opens up the sore again 😓😭