nevergonnaletyoudown

Got a 2001 Mercury Cougar, automatic trans with 90k miles. The past week I've gotten stuck in snow a couple of times and have had to punch the accelerator in reverse for extended periods to get out.

Now today I just noticed that reverse is not moving the car until I get to around 2000-2500 RPMs (even if I wait a while after shifting to reverse, the car refuses to move backwards until I hit this RPM range). Previously the car would pretty immediately start moving backwards from 1000-2000 RPMs. Forward gears don't seem to be a problem, I took the car out on the freeway and noticed nothing wrong, it's only reverse that is presenting a problem.

Is my transmission toast? Any possibility it could be something else, or at least something that wouldn't require a replacement or rebuild?

The majority of the clubbing crowd seems to be 21-29, but I still run into people in their 30s (and some even into their 40s) that are still into the scene. Is there an age considered "too old"?