Abdullah Obeidat "I am leaving it in rice (just like you guys recommend)" definitely not. Nobody on this site recommends rice! We absolutely despise it! There is no room for rice in repair. Rice is great food but not a tool. Take it out of the rice. IT DOES NOT WORK
What we do recommend is that you no longer try to turn your phone on, try to sync it or otherwise use it. That can make a bad situation worse.
The very first thing I would do is to disassemble it by following this guide. 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. Use a soft brush 90%+isopropyl alcohol and clean it very, very thoroughly. You must remove all the EMI shields from the logic board.For a proper cleaning, use this guide. It was written for a 3G but it is 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. Do not use drinking water, if you need to use water, use sterile water. 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. The best cleaning would of course be through an ultrasonic bath. so if you can use that. After you have done all this, reassemble your phone and only then can you perform a proper troubleshooting. Keep in mind that water damage is the hardest to troubleshoot and to repair.