This is freshman year college philosophy Gail - which you'd know if you'd been to college!
The fallacy, or defect with Plato's allegory is the suggestion that because our knowledge is imperfect, knowledge is not possible. This is often extended to an even more nonsensical notion - that our "feelings" and "beliefs" are just as valid as any other means of "knowing."
Plato's trickery is often used to invalidate knowledge - or to try to draw some equivalence between knowledge and opinion or belief. The latter you've done yourself. It's clear, based on the things you've posted, that you don't understand the difference between a fact and a belief, or a belief based on an assertion.
For example, the "golden plates" of your religion - whose existence is based on assertion and belief and appeal to authority - another logical fallacy you'd learn about in Freshman year Philosophy 101.