A photo would help but usually the best answer is to repot it in a fresh mix for cymbidiums, trimming all the old rotten roots and rotten pseudo bulbs (BBs) off. Leave a couple of healthy but leafless BBs to support the new growths as well as healthy roots which are firm to the touch but
short enough so that they do not touch the bottom of the new pot you place the division in.
However, if you do not have any new growth and all the bulbs feel soft and mushy, your plant is probably beyond help.
You do not say in which part of the USA you live and where you place your Cymbidiums will vary with your climate. But in most areas of the U.S., putting the plants outside in 50/50 sun during the summer until frost is the best way to go .
Shoot us a photo, if you can, and we will see a little better what, if anything, can be done to save your plant.
Cym Ladye