I have said some version of the same handful of sentences to dozens of new mothers in our congregation now, usually in a hallway or over a meal I have brought them. You are not failing. This is genuinely as hard as it feels. Ask for help before you are desperate for it. Your baby does not need a perfect mother, only a present one.
Isaiah’s image of God gently leading those who are with young (Isaiah 40:11) has become my model for how I try to speak to new mothers myself — not pushing them toward a standard, but walking gently alongside wherever they actually are. Every new mother I meet is carrying more than she is saying out loud. Gentleness, I have found, opens doors that advice alone never does.