My car does not shift into reverse. when its in drive it wont shift into higher gears.

What is your question?

When the car is in idle it make a fluttering kind of noise. The car does drive but wont shift into a higher gear so it only goes around 20 mph. when trying to shift the car into reverse the fluttering noise stops but the car doesn't move. the transmission fluid is OK and this is the first time this problem has occurred.

What makes this problem better or worse?

its has not been getting worse.

How long has your 1995 Buick LeSabre had this problem?

2 days