Wow! Your puppy was too small and too young to be taken from its mommy. I've never litter-box trained a puppy. I train mine to ring the bells to go out. Mine have always gone outside during the day and on pads in the attached garage at night and in inclement weather.
I hope you have some Nutrical in case your puppy has some hypoglycemic episodes. Could save its life.
Good luck.
