Hi, I think your orchid needs more humidity. Root rotted orchids are best put in bags. You can water the plant, then put the whole plant + pot in a clear plastic bag. Seal the bag but open daily for a while to avoid stale air. When closed, there will be a "mini-greenhouse" for your phal, because the air inside the bag will become moist. Floppy leaves are caused because the phal is dehydrated--it's losing water faster than it's able to replenish it, so the leaves become wrinkled. You can mist the inside of the bag, the mix, any roots to increase humidity, but do that only in the morning, and don't let water touch the leaves because in a closed-in environment mold can grow quickly.
It's best not to fertilize anymore. Just water carefully, trying not to cause more root rot. You'll just have to wait until a good root system is developed (by then the leaves should plump up), then remove from the bag, and treat it like a normal plant. Good luck! It may take a while, but be patient!