Ok, so I was on the highway tonight pushing the needle to 60. When I got to 60mph, I should have been in 4th gear (I have an auto). I was practically gassing the car to go faster, but my car sounded like it was struggling to get higher (high whirling noise). It was barely accellerrating (1-2mph per second more) and it was stuck at 3000rpm and didn't climb higher as I tried to accellerate more. From 1-3 gear, I have no problem reaching as high as 8000rpm. Any ideas on what can be wrong?