CowGirl...
Things you have likely already done:
Check tranny fluid levels.
Check for tranny leaks.
Information I Need:
How many miles?
Do you tow on a regular basis?
What is the approximate weight of yoru tow?
Initially, sounds like your clutch plates are worn, or, you could have solenoid troubles, which was a problem in 2001 trannys.
Take it to a Dealership, or to your trusted mechanic, and have him plug in a diagnostic tool, and read the codes.
Mountain West Diesel