My baby is 5 weeks old. I was breastfeeding, then expressing my milk and feeding by bottle initially to top him up as he has a high palate and does not get enough milk by breastfeeding alone. Then his appetite grew and I didn't produce enough milk to keep up with him so started to give him formula as well.

He is ok when he drinks from the bottle but when he breastfeeds he practically vomits all the milk he drank. He sucks as before but as soon as I go to burp him he vomits heaps. I get very tired and fustrated and sometimes give up breastfeeding him. I feel bad and selfish.

I have noticed that sometimes when he breaths his chest sounds congested, is that normal? Maybe he can't breath properly on the breast but I have tried different positions

Any advice would be appreciated