Manoel, you did not tell us anything about what you did after the phone got completely wet. You will have to at least disassemble it and clean everything with 90%+ isopropyl alcohol. That includes very cable every connector. Check for any obvious damage. After that replace the battery and reassemble your phone. If your battery should still swell up after all that, it is overcharging. That would mean you are having trouble with your power management IC. Here is a decent video about how to disassemble your phone and for the cleaning, check this video. Even so it was written for an iPhone, all the points are still pertinent to your phone as well.