I was the same in the beginning too hun, especially with DS1. In these early days, your hormones are stimulating your supply, as well as your lo feeding. Once the postpartum hormones drop off, you will find that your supply settles down. Some mums still have oversupply after the first weeks but even then not to the extreme that you are finding now.

There are reasons why some mums don't make enough milk and thankfully they are not too common - they can be hormone related such as if there are thyroid issues, some mums have insufficient glandular tissues and there are some other medical reasons. However feeding to routine rather than feeding on demand can also affect supply, and things like birth interventions and mum/baby separation can make it harder to establish a supply. So sometimes it is not that the mum can't produce enough but rather that she's not been given the right information and support to produce enough, or that she's had hurdles that have been too hard to overcome.