Howdy, Chandler, sounds like a nice place you've got. As CJ wrote, it certainly sounds like you've got "Green carp syndrome", in which the bass have basically eaten themselves out of their food supply. The overcrowding of small bass results in very intense depredation upon the BG and crappie, leading to excellent panfish sizes, but few BG or crappie are reaching sizes to be prefered forage for larger bass.
You are truly blessed to have a body of water of this magnitude, but its size also makes corrective action difficult.
In my experience, the most imperative management priority at present is to remove as many bass as possible, pronto, by whatever means you can divise/afford. Fishing tournament with friends? Church group[s]? Boy Scouts? Shocking? A few days off work in the spring, with a couple buckets of minnows and you could make a big dent yourself, I would guess. Whatever it takes to remove several hundred of these eating machines.
Once you get the bass numbers down, you can work on increasing the forage base-but it'll be hard to make much progress without getting the bass numbers down. As Walt noted, shad can make a big difference, but the bass you've got will really hammer them at the size typically stocked, and they're not cheap.
