iPhone 4 not going to sleep from the button

Hey everyone. So I dropped my iPhone 4 in a toilet on new years.... stupid of me I know. When I got home I put it in rice overnight and in the morning it seemed to be working fine, except that the power button isnt completely working. When the phone is on I cant make it sleep or turn it off, but when my phone is off I can turn it on by pressing that button. And I can take screen shots when my phone is on too. So I assume the sensor is still working because I wouldnt be able to do all that otherwise. It also keeps randomly asking my to slide to power off. My phone will be sleeping or I'll be doing something and all of a sudden it will lock and the slide to power off button will come on. I'll cancel it but then it will flash back on and off a few times. So frusterating!!! I'm sorry if I have repeated a question someone else has previously put on here, I took a look but couldnt find any. Please help me!!!

 

It was in my back pocket and I forgot about it in my 'state', so when I pulled my pants down... SPLASH! Totally my fault...