my son is almost 4weeks old. I've been breastfeeding since day 1. he's been skiing really good with it no issues. I started not to produce enough milk so I've been supplementing with formula a few feeds for the past 4 days. my son used to have a poop diaper every change when it was just breast milk but since I started formula he hasn't had one hiking on 3 days. I feel horrible. like I let him down. here eats too fast as well and he will fall asleep before he will burp sometimes then throw up when you lay him down. I'm just really emotional right now and fell like I failed him.