Feel rejected as a mom

My 16m boy prefers his dad over me. He would call him papa ever so sweetly and want him to carry whenever he’s around. He runs to his dad when we are out and would push me away to get to his dad. While I know and read it’s a phrase, I can’t help but feel rejected as a mom. And I’m blaming myself for not persisting in breastfeeding him long enough to form a bond.