M.K.
This actually sounds pretty normal to me. My breastmilk dropped dramatically around 14mo and that's when I started to wean and do the switch over to cow's milk. I think you need to either go formula or cow's milk while at daycare so as not to confuse him and then just breastmilk at home since you want to continue to BF which is awesome by the way. Don't let daycare give him any subsitutions and you should do the same while he is home during the day to keep it consistant. He will drink when he is thirsty. If the waking at night is a new thing could he be teething? Sometimes nursing can help soothe those sore gums. Try teething tablets and rock and hold him for comfort he may not be hungry at all but just needs some comforting.