How to fix iphone 6 plus?

I was with my friends and when i went to sit down on the toilet my phone fell out into the water. I quickly grabbed it, turned it off and shook off as much water as i could and i then went out and out it under the dryer. For the last 3-4 hours i had it in the sun so the water would evaporate and the screen can now be turned on but is constantly changing colors, only lines run across screen, screen doesn't respond to my touch. I have now put it in rice. I'm extremely worried because this was my mum s warranty phone meaning i can't get another and i've only had it for about 4-5 months after losing my other phone. WHAT DO I DO?

Learn how to use the toilet without your phone. You drowned the poor thing. Bury it.