1996 Honda Civic car won't go

I was driving today and went over a curve at about 35 mph. In the beginning, i didn't notice anything strange so I kept going. Drove about 10 miles on the highway, and then stoped at a red light at the end of the ramp. When I took off I noticed that the transmission was acting up. It seemed like it was stuck in first or secend gear. I stoped at another light, and when I tried to go, the car would not move. I can switch to D, N, R, P but the car won't move. I noticed it had a transmission fluid leak. Is the transmission gone, or I just need to stop the leak, refill the fluid and it will be fine?