Can using the wrong transmission fluid ruin my transmission in my Chrysler vehicle?

I have a 97 Plymouth Grand Voyager. I drive like a grandma and never had any issues with shifting (i did have a small transmission leak, but no issues with the transmission except for when I first found the leak - it wouldn't shift into drive or reverse - but didn't move it out of the driveway!). 2 days ago, my bf topped off my transmission fluid for me, and I didn't even think to check and see if it was the special kind for Chrysler's. After he topped it off (he used approx 1 quart) I drove for about 30 minutes and suddenly my van stopped shifting properly. I got off the highway and after stopping at a stop sign it wouldn't move, so I gassed it and it slammed into gear - I couldn't get it to go faster than about 20 mph. I managed to get pulled off the road, however I tried to drive it in a parking lot and the same thing kept happening (reverse and drive both take at least 15 secs to do into gear unless I gas it and "slam" it into gear). I am going to look into it and see what kind of fluid was used, but if it was the wrong fluid, can it be fixed by draining the fluid and adding new? or is the transmission a done deal? I can't afford another car right now, so anything I can try would be great! Thanks