My 18 month old has resorted to only eating crackers. Nothing else.

I have talked to his doctor. MULTIPLE TIMES! All she says is take away juice, and only let him drink soy milk because juice apparently fills him up to much. So I took away juice. He still won’t eat. And hes making his father and I worried about him.. I even started giving him pedisure but the doctor told us to stop giving him that too..

he does eat waffles and pancakes in the morning but then he literally stops eating the rest of the day. We give him PBJ and he he just stares at it and refuses to eat it. Then when it comes to dinner he refuses to eat anything so I give him a fruit pouch and crackers.

I’m really worried, and I don’t know what else to do :/

Has this ever happened to anyone else?