Tom, You stocked at least 100 extra bass and need around 1000 2 to 3 inch bluegill immediately. You also said some perch and some cats. How many? Both are top line predators, compete with the bass, and everything is trying to make a living off fatheads and the few baby bluegills that survive past fry stage. The energy gained per meal is not equal to the energy expended to get it. Thus, no weight gain. We call that anorexia in humans. When I stand sideways and look in the mirror, I can tell whether my calories consumed versus expended are in balance and I ain't having the same problem your bass are. You are feeding pre teen and teenager fish. At that age, just like humans, they are eating machines and need a lot of groceries. You have too many voracious hogs feeding at the trough.
Reread everything Bill Cody said. Read a bunch of the stuff here and you will see the problem(s). Toss a hundred or so bass over your shoulder or eliminate other predators. Get rid of the hybrids totally. Hybrids don't give, they just take. Add 1,000 bluegill while you can buy small forage breeding machines instead of larger ones ($$$$$).
Bill also mentions proper stocking SEQUENCE. He means timing. Fenders should have told you to stock fatheads and bluegill, let them spawn, and then later add predators. Its about like putting a coyote in a field with only some baby rabbits or stocking cows while you are planting grass. Lousy timing. The fish farm didn't do you any favors.
It is possible that you might have other problems. Have you checked your water quality? However, starvation is the immediate problem.
