Help! Very low milk supply and baby won’t take bottle

She is 4 mo and she was exclusively breastfeeding. This last appointment her pediatric was very concerned about her weight. She gained 1lbs in 2 months. The doctor says my supply is low because I got my period 2 months ago.

My baby won’t take the bottle. I’ve tried several nipples, including the natural rubber kind that’s shaped like her pacifier.

I’m desperate! I’m testing fenugreek, oatmeal, brewers yeast... I’m drinking more water and eating better.

I want either my milk to come back or her to get used to formula but right now none of this is happening! 😩😩😩 I need your tips and suggestions!

PS.: we also just started on solids but she won’t eat much of it, of course.

UPDATE: after a lot of pumping after nursing, fenugreek and thistle berry supplements my supply is back up a little. It’s better by the end of the day until early in the morning. On Monday she weighed 12lbs and 8oz. Today (Thursday) she is at 13lbs. I’ve been keeping up with solids and formula too 3x a day (I actually make it very watery, I mix the pumped breast milk + formula + tiny bit of sweet potato). I’m not feeling a 100% confident to cut off her supplementing, I will wait until next appointment to hear what the doctor says. To everyone telling me to get a second opinion or calling her doctor a bad doctor. She has a great reputation, she is one of the bests pediatricians in Raleigh and she is also a Lactation consultant. I’ve friends who are parents and are pediatricians in specifics areas and back me up with the feeding. You will find anything you want on google that are da dangerous and can be “deadly”. So PLEASE don’t add more stress to people’s life telling them what they have to do. This has been a very stressful phase for me, i never thought I would have this kind of problem at 4months in and people coming and telling I’ve to ignore my doctor’s advice because google tells you so, it’s just very annoying and stressful. I’m feeling very lost and all I want is my baby to be healthy and I’m feeling like I’m a failure. And I will definitely ask her about the tongue tie. That’s a good advice.