1996 Chevy Corsica Won't Move

I have driven my corsica for around 190000 miles. I've never had any problem until recently. About 6 months ago it was having difficulty shifting gears. It is an automatic transmission. I checked the transmission fluid and it was low. So I added some and the problem went away. The other day I went outside and started the car and put it in gear and it wouldn't move. I can put it in any gear. I found out it is stuck in neutral. No matter what gear I put it it, including park, I can push it with ease. When I checked the flud again it said it was high. I was told that it could be the torque converter is stuck. That I should try unplugging it and plugging it back in. Any ideas?