I had my baby at 16. I was a child and didn’t take care of him, so my stepmom quit her job to be a ‘temporary mom!

Now, at 20, I’m ready to take my kid and go. My stepmom refuses because ‘she got too attached and said, You’re still immature and not worthy of being a mother. He’s safer with me! She even warned that she’ll prove I’m unfit. My dad was silent. That night, the house felt weird when I came home, and I heard crying in one of the rooms. I entered and was horrified to find my dad weeping. The bedroom was half-empty-my stepmom’s belongings were gone. She had packed and left. My dad handed me a note she left behind. It read: “You were the one person I thought would stand up for me, but you let me down. I gave up my career to raise your grandson, and you let your daughter take him back as if I didn’t matter. Now I’m leaving you, and I’ve taken the money I would’ve earned during those four years.” My dad was devastated, but I think my stepmom was unreasonable. Did she really expect me to leave my child with her forever?
Sydney