Hello everyone. Can you tell me who fed or has been feeding our baby?

Hello everyone. Can you tell me who fed or has been feeding our baby? We've been exclusively breastfeeding for almost a month now and everything was going well. Today, our daughter slept for a long time, but milk came in, so I sat down to express... I felt kind of embarrassed, but it seemed fine, but closer to evening, I started feeling very much pain in my chest and it was so hot, and I felt like I had a cold, there were no temperatures, but my bones hurt and my chest was so hard (it hurts to touch) and slightly red (?). I used to express about 30-60 ml from one breast, but today I expressed 120 ml from