Iphone 7 water damage

Hello everyone,

So i went to Apple store this morning to have my iPhone 7 checked because i noticed yesterday that portion of my phone screen, mainly in the center about half an inch, had like white thin lines and discoloration as well. At that point, i turned off my phone and got worried because the day before it happened, I've decided to clean my phone by running it down with water from the tap for about 3 second but dried it off quickly with a towel and left it to dry overnight before charging. Honestly, I don't really know how the water got it my phone in the 1st place, but according to the apple technician that i spoke to earlier said that it can no longer be repaired as he found liquid inside and some of the components in the phone were already damaged. I have not even had my phone for a year and apparently apple does not cover liquid damage. So is my iPhone is hopeless? or is it still repairable through third party stores? Many thanks.

PS. I'm still wondering how the water got in my phone because i have seen a lot of youtube videos where iphone 7's are submerged in water for more than 30 min and phones are still working perfectly afterwards, and in my case i only ran it down with tap water for 3 seconds then water somehow got in 😐