I'm so sorry. Good luck at the vet! I hope you are able to get an appointment soon.

Because of the bloating and convulsions, it sounds to me like it may be either Red Leg (Type of bacterial infection) or Dropsy. Both are treatable, but unfortunately not always curable. The vet will probably give you come antibiotics to soak her in. Separate her from your other frogs and put her in a small quarantine tank with just a paper towel substrate and a little hide. Cover the outside of the of her quarantine tank in paper to help keep her stress level down. Good luck! Hope she pulls through.