K.P.
Just stop. It's actually as easy at it sounds. If you have decided that you are finished (which you also decided back in November) then you need to close-up shop and offer him only milk, water and table foods.
You don't need anyone to watch him, so I don't know why you would see that as a barrier. Put out a straw cup of milk along with his breakfast, then again with lunch, snack and dinner.
This is about your ability to stay consistent and say "no" to your son. He will scream, cry, tantrum and probably go on a "hunger strike" for a day or so, but as my pediatrician told me... he won't starve himself. When he realizes that he's hungry and you aren't going to give-in, he will eat. When he realizes that he is thirsty and you aren't going to give in, he will drink.