Dodge Ram 1500

I'll try to keep this as short as I can. I was driving my 1998 dodge ram 1500. About an hour or so into my trip, the truck started acting funny when I was accelerating up a slite incline. It was as if it could not shift out of 3rd gear. It's an automatic. When I was trying to accelerate, it started to bog down. I could'nt speed up, even though I had the peddle all the way down. I pulled over, shut the engine off, checked my Tranny fluid. Everything seemed to be up to level and clean. Started it back up, and all of the sudden the"Check engine" light came on, and would'nt go out. I tried to drive it again, but it continued to do the same thing. So I pulled off and shut it down. I started it 2 more times and tried to drive it down the road. Still it did the same thing. Seemed like it would only shift twice. I shut it off again and was waiting for a tow. After about 15 minutes, I started it up one more time. this time however, the "Check engine" light did'nt come back on. So I started to drive it again, and it seemed like it was acting like normal again. I was able to cruise at 50-55 mph, no problem. I still got a tow back home, cause I was'nt sure if it was completely back to normal, and did'nt want to mess anything up. Does anyone have any suggestions or have had this happen before? It's the 5.7 liter (360 ci) engine. Gasoline. I replaced the ABS sensor on the rear differential over a year ago. Any suggestions would be greatly appreciated. Thx for reading this. Rick