Please Help! Decelerated Then Stopped!

While driving at about 60 mph, my vehicle made a strange vibration and decelerated to 50 mph. When I tried to accelerate, the rpm's would rise but I could never get above 50 mph. Approaching a stop sign, I feared my car would completely stall and I would be stuck in the road so I pulled onto the shoulder. As soon as I came to a complete stop the engine shut itself off. What could cause this? I'm not sure if my car will restart- I was too afraid to try. If anyone could give me any idea what could have caused this I would greatly appreciate it!!!

Welcome to AF! Unfortunately this sounds like your transmission may have gone out on you. The engine probably died because the torque convertor solenoid locked the convertor and when you stopped the engine died. The key here is the fact the the engine would rev but you couldn't go past 50. Did it feel like the transmission was slipping? Try to restart the car and see what happens. If it is in park and the engine starts then the engine is probably alright as once the power is shut off the convertor should unlock and allow you to restart it. If you put it in drive and the car stalls then you will probably have to have the car towed to a repair shop.