First, I wanted to say, don't give up. I have had lots of problems with breastfeeding, low milk supply being a constant. I gave upi BFing my eldest son in the first week because of a similar situation. I was forced to supplement because of his size (9 lb 6 oz) and they said that his blood sugar would drop if we didn't. They also told me that he would still BF if he had a bottle. Uh, no.
With my 2nd baby, I stuck with it for 2 1/2 months and gave up due to very persistent thrush and supply issues. I thought of BFing as an all or nothing deal and looking back I am sad that I didn't try to keep at it as long as my son would BF, even if he ended up getting a lot of formula. There is so much value in every drop of BM and in the simple act of BFing.
With my 3rd baby, I struggled with supply and thrush again. I did a lot of supplementing at the breast and pumping to increase supply. I made it to 9 months BFing her.
With my youngest son, I felt like it was probably my last chance to BF, so I really did a lot of research and planning. I was committed to making it to 1 year. Then, I was thrown a curve ball when on the second day of life it was clear that there was something wrong. He went to the NICU and I ended up having to exclusively pump because he was NPO. He went on to have surgery and spend almost 5 weeks in the nursery, where he was not allowed to BF at all. So, I had to EP and give him my milk in bottles.
When I brought him home, he was hesitant to nurse. I was determined to get him back to the breast. With the disease he has it was super important to me to BF him. He had to have part of his colon removed and he needed BM since that was easier to digest and a natural laxative. I also wanted him to have the natural immunities because of all his exposure to illness with his frequent hospital and doctor visits. So, when I brought him home, I cut out all bottles and supplemented him at the breast. Once I did that he came around and nursed.
I took galactagogues, pumped to build my supply and I managed to exclusively BF him until 1 year. He still nurses a little now, at 26 months old. I found really good support and resources online and at LLL.
I would also recommend getting your thyroid checked. Some mamas have problems with their thyroid function postpartum. Also, find out what your number is and verify that with a knowledgeable LC. Many doctors do not realize that the thyroid numbers for a lactating woman are different that regular. So, if they just tell you your numbers are good, make sure they are comparing them to the correct standards.
PM me if you ever need support or want to know about some of the things that worked for me.