Hello everyone! Can you please tell me how you feed when breastfeeding…

Hello everyone! Can you please tell me how you feed when breastfeeding? How much does feeding and drinking depend on milk supply? In the first month, my son had enough milk, but now he's very nervous on his chest. He doesn't take the right breast at all, and only takes the left one for the first 5-10 minutes well, I hear him swallowing, then he starts to be nervous again, crying. I don't know what to do anymore, the increase in the first month was 1.5 kg, it seems like there should be enough milk, but he still gets nervous. The left breast is 1.5 sizes bigger than the right one, if I don't hold it