Feel guilty but I hope I'm doing thw right thing..

I really don't need any nipple nazi's calling me a terrible mom for my choice so if you're just gonna be judgemental plz leave this post. I had to put my baby on formula. She was allergic to something in my milk. I tried cutting stuff out but literally nothing was working. She would get really bad rashes after feeding. She vomiting a lot after. Wouldn't sleep and was losing weight at an alarming rate. I'm not against formula, but with all the parents shaming that comes with it I just wanted to try to best feed and be the best mom I can be. But something in my milk was making her really sick and we couldn't figure out what is was. Her weight was so bad and so low. After her pediatrician talked to me he said "I know you really want to breastfeed, but if we can't figure out what's in it that's making her sick, we may need to try formula." I cried because i felt awful. She always looked so uncomfortable after a feeding, and would get rashes, and vomit so much. And me not being able to figure out whats in my breast milk causing it made me feel worse. I tried for a long time, but I knew her health is what's most important. And in my situation my breast milk is not what was healthy for her. He gave us a prescription for a type of formula and since she's been on it she's been great! She sleeps more. She isn't uncomfortable. She's an overall happy baby. I am so happy not to see my child in pain anymore. I do have this guilt for not being able to breastfeed her, but I'm so happy she's happy now.