Want to start weaning but baby wont drink milk

Hey ladies. My son is 13 months. Iger's stopped pumping at work, I'm currently part time and only working 3 days/week. Daycare offers milk/water and my son will only drink water. I've tries soy milk, coconut, almond, cow's, vanilla pea protein, toddler formula, etc. He will only drink breastmilk or water. Daycare did get him to drink 2 bottles of warmed cows milk this week and he has diarrhea for 2 days. Idk what else to do. Is nursing 2 to 3 times a day enough nutrition for him? I'm planning on calling the dr this week but just wondered if anyone else experienced this and any tips?