1995 Ford Contour cant figure out problem

Hi, my fiancee and I recently went on a trip that was a little over 200 miles, we stopped to eat after about 100 miles, went to get back on the freeway, and the rpm went to like 3000 and was like it wouldn't shift, stopped and added tranny fluid thinking that was the problem, ran o.k. for awhile, then acted up again, so we stopped at a rest area, and sat for about 1.5 hrs.
we had about 50 miles to our destination from there, only drove 50 mph the rest of the way and car was fine.
The same thing happened on the way back home.
I was told many things from:
1. transmission
2. fuel issue
3. catalytic converter
Any suggestions,
Thanks