i agree with Kate
at this point in time, it's "normal" for supply to settle down. you won't necessarily have an oversupply as you would in the early days - it's more a case of supply meeting demand. and expressing is definitely not a sign of how much bub is getting. i have NEVER been an effective expresser - 1 hour or 8 hours after last feed, i would get the exact same amount.

keep attaching baby whenever hungry. trust that your body knows what it is doing. call the ABA if you need more support. watch baby's output (wet/dirty nappies) - if that is good, they are pretty much showing they are getting enough

your bub will be unsettled at the moment due to the growth spurt and the six week wonder week