I have the same problem too. A math teacher of mines knocked my phone down when we were taking a snap. The thing is the rice myth does not work. It damages the logic board. The only solution is to get your screen/LCD fixed or do it yourself which cost about 30 bucks but takes lots of time. One thing is, don't use rice. Here are some ways you can dry off your phone.
Blowing it off with a blowdryer for 15 minutes or more.
Let the phone and battery separate sit out for a day or 2 depending on the temperature.
Don't connect it too a charger. That will shut down electricity for an average 3 days or 2.
That's all I know about this subject. But it could be battery oil, dead pixels, corrupted screen damage. But if you see it your LCD is already damaged.