Doctor told us to supplement 🤦🏽‍♀️

Today we had our 6 month check up and babies weight completely fell off the chart🤦🏽‍♀️ he’s exclusively breastfed and only takes maybe 6 bottles a week, each time I leave him 3 oz per bottle and sometimes he won’t even finish it. Every other time he’s fed straight from the breast. This is a different doctor than we’re used to and I have a feeling she didn’t breastfeed (which isn’t a problem but I think there’s a slight disconnect). This and last time she asked how much I pumped to make sure I made enough and shut me down and said he needs formula. I’m worried about his weight too but I REALLY don’t want to use formula. Is there a way to avoid it? Maybe starting him on solids? He had another appointment next month to check his weight gain and I already plan to go crazy with pumping to hopefully boost my supply. I really enjoy breast feeding and really don’t want to give up😞 I just feel like a failure being told to supplement. Maybe I need to just stop being selfish and give him formula but if there’s anyway I can avoid it I would love to hear suggestions