First off, get rid of the attack speed bandaid. It feels horrible to play with. Just boost her base AA speed and remove all AA speed from her kit at this point.
Second, Moonfall has a rediculously long cooldown for what it actually does. This move needs a total rework actaully. You could just change her passive to something like, "Diana moonfalls whenever she hits an enemy champion or large monster afflicted with moonlight.
Change her E to an actual AA speed booster and grant magic damage on hit passively.
And there you go, Diana is fun to play again.