Struggling with baby part 2

Baby girl spent better half of last night screaming her head off like she was trying to go poop but just couldn't. Shes been passing stinky gas a lot and has had two poopy diapers but they've been dark green. The pediatrician thinks its from where we've switched formulas and its messed with her belly. She also thinks that she has developed Colic. 🙄 A family member bought baby girl some hylands colic tablets and im afraid to give them to her. Anyone had any success from giving their babies these tablets or any advice on navigating colic. Her screaming kills me and I hate not being able to fix whats wrong. She is 3 weeks old.