Auto Tranny Not Shifting!?!

Hey I Have a 97 Maxima SE, and the other day i turned the car on and went to reverse and it started shaking, like it was going to stall, i thought nothing much of it, because the car was cold, so i drove slowly then like 5 minutes later, it felt like the auto tranny did not want to shift, the rpms would jump from 1.5 - 2.5 until i let go off the gas... does anybody know what this could be, could it be the Torque Converter? Any Suggestions are greatly appreciated..

check you tranny fluid, when that happened to my 90 se auto it didnt have enough tranny fluid to shift gears. on the dipstick it should tell you what kind you need.

its prob not the same thing, but i had parked in my driveway kinda weird and had left side up in grass(theres a small hill) and when i started up the car the rpms did that and the whole car was shakin, but i got off the hill and stopped. is this bad or is it jus where the car was sittin weird for so long???????