While driving up a highway ramp I lost all power in my 1996 Chevy
Cavalier (2.2; 99,000 miles).  The car is an automatic.

When you hit the accelerator inn D, 1, 2, or R, the car will rev but
won't move.  No respons what-so-ever.  And when you go from D to 1, or
D to R, the car doesn't budge like it usually did.  Usually you could
feel the car lunge just a little bit.  Not anymore.

Transmission fluid level is fine.

Does sound a little weird under the hood.  Kind of like their is a
helicopter flying under the engine.  Don't want to be too dramatic and
blow it out of proportion but the chop-chop-chop is loud enough that
it can definately be heard over the normal engine noise.

Is this a classic sign of something?

I can pretty much figure out it has something to do with my
transmission?  Is this what they're talking about when they refer to
the torque convertor (though on the internet, it sounded like a bad
torque convertor was related to the car stalling/surging)?  Sounds
pretty messed up.  Anyway, if telltale, is this an expensive
venture?

Any insight appreciated.

Thank you.