I have had clients do formula for the first few weeks. Usually because they aren't quite a year due to mom taking mat leave earlier then baby came.

I would chalk the eating issues up to a new environment. If I were you, I would keep with your schedule. If the baby learns what to expect from you next it will be more comforting.

I find the first 3 weeks with a 12 month old are the hardest. It's a huge change. I once read an article that said that baby's are best to transition between 6 and 12 months. Once they hit a year they get difficult. The start with the attachment issues.

As for today... if he's just taking formula then let him have what he will take. I always win with some cheerios! Then they tend to continue to the good stuff from here.

Lots of smiles from you and calming words, calming sounds. If you need a break, put him in a safe spot and take a small break.

The first few weeks are the worst. I hate transitioning in new kids.