At 3 months you may want to get a Vet's help to make sure something else isn't wrong with him.
I have a very special white cat too, farm girl, 7 yrs, got her at 3 months, baby teeth were just starting to fall out then,
she mostly licks up the gravey when it comes to canned food and perfers dry food,
got bad diareah when switched to higher grade Natural Balance and Chicken Soup dry foods,
but slowly she got adjusted, were trying a Maximun Nutrition Indoor formula, chicken is 1st ingredient,
But you have a kitten yet and may have to wet some kitten food for him to make it easier to eat,
heck, go buy a bunch of different kinds, and what he don't like feed to the birds, try cat/kitten milk too.
but remember if he hasn't ate for 2 days and he's only 3 months you'd better get something going quick,
tommorow would be day 3 and seeing a Vet better be on the agenda for the little fella.