The only way to possibly get your game console working correctly again is to clean it properly, by dis-assembling it and using IPA 90%+ to clean all the affected parts as outlined below
The water causes corrosion and provides circuit paths for the electricity which were not in the device's operating design and could damage the components.
First do not turn on your console so as to minimize further damage
Then you need to dis-assemble the device and clean all the affected parts using Isopropyl Alcohol 90%+ (available at most pharmacies) to remove all traces of corrosion and water. Do not use "rubbing alcohol" as in some cases this is <70%, can contain scents and is not as effective. If you do check the label to verify the amounts.
Here is a link that describes the process.
Electronics Water Damage
As always with electronics, especially surface mounted PCBs be gentle when handling and especially when brushing away the corrosion. You do not want to remove any components from the board.
Here is a link to the ifixit teardown guide, which may be of some help.
PlayStation 4 Slim Teardown
Hopefully after you have done all this it might possibly work correctly again.
If this process seems too daunting, take your console to a reputable, professional electronics repair service experienced in water damage repair and ask for a quote for a repair. If you decide to do this, do it sooner than later.