Two contrary things in apples. Lots of sugar, as in all fruit, might have gotten to you, though this is awfully quick. Anybody can be allergic to anything. But apples also have quercitin in them, which is a natural anti-histamine which theoretically would make your ears feel less full. A toss-up, eh? I have this fullness problem as well. Mine was apparently caused by a medication, but it hasn't gone away. Weird stuff.
Stupid me!! But then I did say something about Brain Fog.... Red Delicious Apples, which are a sweat apple to begin with.
(ear fullness from birth defect which, in a meter of speaking, creates a hole on the skull between the inner ear and brain, which is why pressure in the inner ear is important to me).