Underproducing and struggling

Already working with a Lactation consultant so I want to vent mostly, but will still take any tips or advice! My little boy is 5 weeks and breastfeeding has been going great from a latch/bonding/minimal pain perspective, but the poor peanut is just not growing much and I am under producing. He is not LOSING weight, but I'm not making enough for him to gain properly so we've started supplementing with one ounce of formula after each feeding. So very frustrated and feeling like a failure honestly, that I can't make enough milk to feed my sweet son. I know logically that all I can do is try all the LC recommends to boost production and give it my all and the fact that he is fed matters most, but the guilt is real mamas. 😢