2 problems with 96 Bonneville SE

The first problem is that fuel gauge bounces around. One time it will be empty even though gas was put in it 5 mins ago and the next its full.
The second problem is that i went to Autozone and got a scan done on the computer and it said that Trans. Comp. Failure what does that mean? When Im driving it i would step on it, the car doesnt want to shift out of gear until i let off the gas. But when i take it easy it shifts nice. Please help!

Keep it full of gas or drop the tank and check the float. B'villes have problems with the gas gauge. As for the transmission, try replacing the vacuum modulator and check for vacuum leaks, also, change the fluid and filter in the transmission. A can of Trans-X probably wouldn't hurt