Sounds like water got to the digitizer and shorted it, among other things. If you cannot crack it open yourself and dry it out (and that’s being optimistic), you’ll likely need a screen replacement at least.
Given how much ingress of water there was, and if it reached the motherboard/battery, the phone is likely dead. If it isn’t, odds are it will down the road. Charging it was a bad thing to do - obviously water and electricity don’t mix well. I’d be worried about corrosion down the line, which may take its toll days or weeks down the line.
If you can get the phone revived then great. However, I have serious doubts to its longevity. Sounds like repair or replacement to me.