Dehydration. Suggest me some thing.

Hi my son is 2 year old, wt. 10 kg's ht. 2'2". Birth wt 3 kg. He is under wt and under ht. Not eating anything, he just eat 2 or 3 spoon of anything I give. I tried every possible way, like I tried to feed him while playing. But i failed than I tried with books and pen.. His favourite toys.. at last I tried with TV but that is also not working. 200 to 250 ml milk in a day. Fruits veggies roti paratha halwa chocolates Pizza burger. He is not interested in food at all. It was ok till now. As I am a working mom and I have no one in family. My husband is also working. So we are sending him to playgroup. He is not drinking water or any liquid because of that he is not peeing properly He pee is very smelly. His diaper is alwys dry. Please suggest me some thing.