NPK Fertilizer promotes growth really well. I use this stuff for my fertilizer. about a cap full per gallon of spring water or rain water. once you repot this specimen I would lightly spray around it on the top soil and let water drain through naturally and let the plant pick up what it wants. If its still alive you should see some plumping up in a few days and it wont be as squishy. new growth should be visible in a few weeks.
I'm brewing a compost tea right now in a 50 gallon plastic drum with this stuff that I just got: https://www.amazon.com/Organic-Hydrolyzed-Fish-Seaweed-Blend/dp/B00BBLMXVQ/ref= I'm using a half cup of humic acid, about a cup or a little more of that fish and kelp blend, 3 tablespoons of molasses, and about a gallon of compost. Havent made a tea since last year, but last year I didn't use this fish and kelp emulsion so I'm curious to see how it goes. It's basically the recipe that this guy uses: https://www.listennotes.com/podcasts/farm-land/whats-brewing-how-to-brew-3CyljReak0K/
This is the stuff I use.