Engine Rattling And Whining Sounds problems of the 2007 Nissan Altima

I was driving northbound on western avenue busy main street in chicago all the sudden my car started shaking and vibrating as I approach the lighti had to turn my car off put it in park first turn it off and then try to turn it back on to accelerate it only works once until I got to the second main light and my car would not move or accelerate and I was stuck in the middle of a busy main street with cars behind me beeping and driving past me. Not to mention my rpm's we're going all over the place and I could not drive past 20 miles per hour and the car would speed up and slow down on its own and it felt like it was over working itself. Prior to this ionly a week ago that I heard a rattling noise and took it into my mechanic to see what the problem was and the computer told him it was a transmission issue which at this time Nissan had refused to repair and replace based on the warranty because I was over a thousand miles which at that point I never knew or was notified there was an extended warranty otherwise I would have taken in the car a lot sooner thousand miles is only two weeks more of driving for me. Also my rpm's were going all over the place I couldn't even drive past 20 miles per hour and then the car would speed up with the rpm's increasing not only does this present a problem need driving the car but it also created a safety issue I could have gotten hit from behind with my 1 year old child in the backseat crying hysterically and I could have gotten hit moving my own car to safety because I had to get it out of the main busy street and no one came out to help me and I was pushing my car by myself in 20 below freezing weather in chicago. Now it's going to cost me $2,000 to fix this problem that Nissan already knew was an issue never notified me of even with the extended warranty and did not want to cover it because I was over the mileage.