I have a 97 Ram 1500 4X4 with the 5

I have a 97 ram 1500 4x4 with the 5.2 magnum and automatic trans. It starts up and runs totally fine while cold. If I drive for a bit, usually when it gets to full running temp, the rpm's drop and it wont hardly move. If I floor it, it shuts off. It idles very rough and I have to rapidly tap the gas to get the rpm's up, they only go up to around 1000 at most when its doing this. If I let it sit for an hour or two, it starts up and runs fine, until it warms back up. I've replaced the tps sensor, plugs, and wires. What else could be the problem? The check engine light came on and showed misfires and a tranny code (go figure). Need some help asap!