Thank you for using Just Answer. You are in a difficult situation. The ramifications to the child could be emotionally irreparable. I am sure he sees you not only as the surrogate mother, but as the only female caretaker he has known. Especially since you have cared for him since 4 months.
I am assuming since his father has retired, he plans to spend more time at home in a parenting role, and this is what is causing the conflict?
It will be very important for you and the child's father to work together on this to avoid conflict in front of the child. He must see you both as a team working together for his benefit. Although it sounds as if it is already causing some conflict for him.
You and the child's father should meet and discuss your varying values and ways you can combine these for the child's well being. You didn't say if the father is interested, but I hope so, for the child's well being.
If you are unable to do so on your own, I would seek counseling through a therapist with experience not just with family counseling, but with child counseling as well. Most family counselors are able to address parenting issues effectively, if both parties are willing to be somewhat flexible.
If you are not able to reach a consensus on how to raise the child, and the father's decisions stand, please think hard about leaving this child. But also, consider your own emotional health as well. You do not have to live with stress and anxiety over this, but would need to discover how to accept the situation as it is.
Please let me know if you have further questions. Gina