? For any moms who have went dairy free

I know it’s a common recommendation to go dairy free if your babe is fussy and I have been dairy free for 4 months now since my lo was 6 weeks. I should say had because Christmas I had a peanut butter cookie and he had no reaction! When did anyone else try foods with dairy with no reaction? And when did you move on to cheese or pizza? (I’m dying for a slice)