Weaning breastfeeding

My daughter is 20 months old and I have to wean her because her father wants to start taking her. She has been with me 24/7, he came to see her like once a week but has stopped coming and only comes to take our 4 year old over weekend's. I really don't want to stop until she is 2 that has been my goal and he knows it but now doesn't support it anymore :(

Well I want to try something that said to put a band aid on the nipple, has anyone tried it? Did it work?