Lois, Welcome to the Orchidboard, we are so glad you found us!
If it's any consolation, what has happened to your plant is one of the most common things that can happen.
You don't say what you used for medium when you re-potted so we need a bit more information.
Did you use bark? Did you let the bark sit over-night in water to absorb all it could before planting?
Oh, a common, household item to use on root tips after cutting off the dead/rotten roots is Cinnamon.
Just a dusting on the cut.
Hope to hear from you again, and congrats on the anniversary!
Al