Girls, got tangled up in the mixtures. We've been exclusively breastfe…

Girls, got tangled up in the mixtures. We've been exclusively breastfeeding since birth. Two weeks after delivery, I gave her Nutrilon Premium, started constipation, terrible colic. The pediatrician said to give the baby, covered my whole face, switched to Nestle, we ate for a week, the face covered with a crust, although it's okay, and the colic went away. The pediatrician said to switch to Nutrilon Gastro. But I read that such mixtures are harmful and you can't give them constantly. In general, what should I do ?