1993 Dodge Intrepid Transmission?

I have a 1993 Dodge Intrepid that I think is having a transmission problem. I was on highway doing 65 and all of sudden car would not accelerate, just revived up the rpm running high. I got off on shoulder and the car kicked back into gear, but still at the higher rpm, like it couldn't shift. This happened a couple of times last summer, but all winter no problem. What should I do? My budget is limited and I already need to replace outer tie rod, according to place that just gave it oil change.