If you’re latching most of the time and then pumping and getting 60ml, there’s probably 2 possibilities.
1) Baby is not latching well hence your boob is not clearing.
2) Baby is latching well but you are oversupply.
Anyways, excess you can store and freeze to build up stash. As long as baby is producing enough wet diapers, drinking well and no discomfort I wouldn’t worry too much on the weight. As long as you nurse frequently, baby should be drinking enough. 😊
Chloe Chong