@killians this is most likely caused by the water damage. You did not tell us how you dealt with it or how you dried it. I suggest that you treat it like any other water damaged device.
The very first thing you want to do is to not try to restart, sync or otherwise try to use the phone. This may further damage your phone. The next thing to do is to clean it. Disassemble your phone by following these guides. Take a careful and close look at all components and connectors. Truly assess the damage. Look for major corrosion, evaluate the pins in the connectors etc,. Take a look at all connectors as well as cable ends. You will have to remove all the EMI shields. Use 90%+ isopropyl alcohol and a soft brush to clean your parts. For a proper cleaning, use this guide. It was written for an Apple iPhone 3G but all the points are still pertinent to your phone as well. I can not stress the importance of a good cleaning enough, so do it over and over while replacing the alcohol after each cleaning. Do not use compressed air for the cleaning since that can drive liquid as well as corrosion particles into areas that will cause trouble later on. Also, you do not need to leave it to dry for a day. Isopropyl alcohol in the higher concentration will evaporate quickly and dissipate the water. The importance here is the cleaning. Do not forget to replace the battery. This is a must and not an option. It will fail if you do not take care of it now. Of course, if you have access to an ultrasonic cleaner, make use of it. After a proper cleaning, replace the battery and reassemble your phone. Only after you have it properly cleaned can you trouble shoot for what really does not work. Until it is cleaned, anything will only be a guess. Keep in mind that water damage is the hardest to troubleshoot and to repair.