Im experiencing something slightly different but almost the same.
I can't shift into 5 at all. Not unless I am going around 60mph and even at that I gotta push the shift level hard to the upper right and SOMETIMES it'll clunk and go in. On reverse, I can get it into reverse nearly all the time, but alot of the time, it sticks and I can't get it out. I kinda gotta work it to get it out.
I just bought the car, so I am unsure if the fluid has ever been changed.