My iphone thinks it has headphones in?

Ok so i had a otterbox on it but it dropped in the pool its almost completely fine i even used rice to draw almost all the water out which it did but now you can only hear sound with headphones it i know the speakers work and all cuz when i called it my ringtone played through the speakers at the bottom but when i turn the volume up without headphones in it says headphones are actually in when they are not. What happened to it exactly the water damage is gone it works fine except the fact i need headphones what can i do

Try restarting your phone
if that doesn't work then backup all your data and do a factory reset and then restore your data
if none of that works then you have a hardware problem and you will have to go to a mechanic