Oh my, I don't know if I have any good news to give here. That poor thing looks pretty well gone. Around here though they have a little trick called "sphag and bag". You take a plastic bag, place a good amount of sphagnum moss in the bottom, then prep the base of the phal. You need to remove anything black and rotted, apply either physan 20 to kill bacteria and fungus...or you can use a fungicide spray....then dip the base into root hormone powder, shake off the excess and set the plant into the plastic bag with sphagnum. Pull up the sides of the bag a little, leaving the top open for air movement. For about two weeks keep in a shaded area and spritz a few times a day with a mister bottle.
Or....throw that one away and start over. You may need to switch to either a clay or plastic pot and mix a phal bark mix with a little chopped sphagnum moss for moisture without rot. Sometimes you have to experiment with the potting mixes to find what works best for your area. I live in humid Florida and I like to add charcoal to my phal bark premixed bagged stuff. It helps keep my roots from rotting.
Hope this helps