Water damage

Your iPhone is, most likely, damaged. I suggest that you stop using it and be sure that it is powered off to prevent any further damage. The Apple warranty does not cover this type of damage and any repairs, if still possible, will come at full cost to you ... unless you elected to have purchased an AppleCare+ plan ... then they would come at a lower cost.

At this point, I suggest that you take your phone to your local Genius Bar or to an Apple Authorized Service Provider to have them assess the extent of the damage and provide you with your options.

Make an appointment at the Genius Bar of your local Apple Store.

You will have to pay for an out of warranty replacement. Liquid damage is not repairable.