Hello Could you please tell me about a 2.5 month old baby? For the p…

Hello Could you please tell me about a 2.5 month old baby? For the past five days, the baby has been restless. Especially the last two days, the breast is not taking well, almost refusing to feed during the day. He eats at night, barely anything in between. The stool is very thick and dark green. When I give him the breast, he starts crying. I have mastitis on my left breast, I am taking antibiotics, could it be from that? But I also give him Hippolyte.