ditto what jhaluska. Most important I would run distilled water through the soil several times to take out all the toxins (plant food) out. Then give it a month to recover. I would also hold off on dormancy until the vft recovers. Just that I would not put a hurt/sick vft in doramancy that could be the final death blow.
Use just pure rain water or distilled water. Anything else could really harm the plant. If you want to increase growth on this website petflytrap.com they sell superthrive which works well I have heard. I would either rinse the soil really good (again) with distilled water to get the toxins out of the soil or you may want to transplant (not really recommended on my part but is an option).