Major problem today. Need help diagnosing

I noticed that the throttle stayed on. The car would not slow down when I let off the gas pedal. I put my foot under the gas pedal and lifted, but that wasn't it. If I put it in neutral, the rpms would shoot up almost to redline before I put it back in gear. By the time I could get to the next exit, it was getting real bad. The brake was barely holding it back. The car was literally taking off like it was floored. I finally got over and shut it off, but the check engine light came on, some smoke was coming from the engine, and a burning smell (probably brakes although it is also from the engine). It was too dark to see anything further. I am going to get it towed in the morning. What does it sound like to you? I have had it for over 5 years and was hoping to keep it longer. Any insight would be appreciated. Thanks...-GT

Edit- closer examination today in the daylight shows that the throttle cable will not retract when I let off the gas pedal. I tried lubing it with a good spray. I can push it back if I really work on it, but once I step on the gas, it will still stay out.