Please help! African Dwarf Frog with dropsy =(

[TinyTreasures]

So we've had our two little guys - both African Dwarf Frogs - for a year now. Out of the blue one of them swelled up like a balloon yesterday. I searched the internet for what to do as it looks like dropsy and so far I've given him a 30 minute bath in 1/2 tsp Epsom salt dissolved in 1/2 gallon water. I also cleaned the tank, did a 50 percent water change, and replaced the filter. So far my other AFD looks fine.

I was going to go to the pet store today and buy antibiotics - Mardel Maracyn Two, but they don't have it. I called around everywhere from exotic pet shops to vets and no one has over the counter antibiotics for my little guy! Even Amazon is out of stock. Please help, what can I do? I can't just let my little frog die!