I have a similar story. My son was older. At 6 months he wasn't interested in solids and being my 3rd bf child I wasn't worried. By 8 months he was growing slowly. He was already being seen at a major children's hospital by a hematologist for immune deficiencies. His two brothers and I also have immune deficiencies but he was the most healthy. The hematologist didn't listen to me about how I thought something wasn't right.
Around a year he was a little smaller than his brothers had been and still not eating. All of a sudden the hematologist decided he was failure to thrive. She hadn't listened to me for several visits and then admitted as failure to thrive. We were there for 3 weeks in a room with a screaming baby whose parents lived too far away to visit. I stayed 24/7. My son's father deserted us before he was born and had never seen him.
I agreed to do just about anything except wean. We weighed before and after feeds. I pumped after feeds. They tried to force feed solids. I tried to force feed solids. It was horrible. They made me see a psychiatrist that thought I was making him not eat to get attention, making him not eat so he would stay small because he was my last baby, that there was something wrong with me because I though it was OK for a 12 month old baby to wake up at night and nurse, you get the picture. My two older sons were from my first marriage and were staying with their father and step-mother. It was a horrible situation for everyone.
Somehow we got out. A couple of weeks later they wanted readmit to put a stomach tube in. I had been calling doctors to try to find someone else to see him. Since he was being seen by the "great" children's hospital no one wanted to take his case. The children's hospital threatened with CPS if I didn't do what they said. I had to take my two other children there because they needed blood product transfusions for their immune deficiencies every 3 weeks and there was no where else doing pediatric transfusions.
I found another doctor and hospital the day before the stomach tube hospitalization. My son had hand, foot and mouth disease so when we were admitted we got a big private room. They brought me a bed and brought me meals. His brothers could come visit. No one was telling me I was crazy.
It turned out he had tactile sensitivities and he didn't like food in his mouth. The doctor and the occupational therapist had just been to a conference on helping kids with tactile problems. He was eating in 2 days and we went home in 4 days.
That was 20 years ago. We now know that failure to thrive is one of the 10 warning signs of having primary (hereditary) immune deficiencies. There wasn't evern a name for the kind of immune deficiency we have back then, Common Variable Immune Deficiency (CVID). So he had both immune deficiencies and tactile sensitivities and if he hadn't been breastfed would have been one very sick kid. He might not have survived.
Now he is 6'4". I have really starved him! He is taller than both his brothers.
The children's hospital hasn't changed, I still hear horror stories from parents.