Okay so I was trying to wean my baby off breast and switch to formula only but he refuses to take…

Okay so I was trying to wean my baby off breast and switch to formula only but he refuses to take formula half the time and will only drink my milk I'm going to take my ADHD meds soon being the reason I have to wean but he will force himself not to drink the formula until I let him breastfeed what should I do