Supplementing Breast Milk

So, my son is not gaining enough weight and I went to a lactation consultant yesterday. He had actually lost an ounce from the weight check the day before at the pediatrician's office. He was weighed before and after the feeding; my supply is not enough. I have to supplement with formula and pump my milk, as well as nurse. I did not want to give him formula but he does medically need it. My pediatrician didn't even suggest it yet, but I need to pump my milk to get ahead and supplement with formula in the process after feedings. Anyone else doing this? It is overwhelming and I have done nothing but nurse, supplement and pump today.

Anyone else going through this? I do feel a lot of guilt for not being able to fully provide and not realizing he has been legitimately starving. Cheers to everyone bottle feeding and breastfeeding. This shit is really fucking hard.

Merry Christmas!