Breastfeeding : cluster feeding /milk supply

Ariel

So my son is about to be 5 weeks old. I am breastfeeding him only and I want to increase my milk supply. I am trying to breastfeed him and then pump after he eats, but sometimes he wants to eat again like 30 min or an hour later. I put him back on my breast, but then he gets fussy and crying because there isn’t milk coming out I guess as fast as he wants it. I try for about 10 min to get him to keep sucking and sometimes I give up and get some milk I previously pumped. Sometimes he wants to eat again right after I pump and then I have like no more milk for him. I still put him on the breast, but I feel terrible because I feel like he’s not getting enough. Other family members are making me feel worse telling me my baby is starving and I need to supplement with formula if I don’t have enough in my breast at some feedings of the day, but I heard that decreases your supply . What can I do when he’s fussy and I feel like he’s not getting enough? And what can I do to increase my milk to store?