This is most likely a surgical emergency! Kindly take the child to the hospital preferably the Children's Emergency room of the closest Teaching Hospital NOW

Bad breath or Halitosis in
children can occur due to several reasons
like poor oral hygiene, mouth breathing,
tooth decay, gum disease, infections in the
mouth, bacteria on the tongue, dry mouth,
tonsil stones, foreign objects in the nose
and some medical conditions.

It is natural for babies to pee more if they take lots of fluids be it water or juice..
However to be on the safe side and rule out disease conditions that could make children pee a lot and often like diabetes or Urinary tract infection, I will advise you to see a doctor for proper evaluation including urine laboratory tests.