iPhone 6 plus is dead and won't charge

Hey so I have the white iPhone 6 plus and I took it with me on my vacation. It rained half the time, but I was careful enough to keep it in my purse and every time I took it out, it was always dry. We leave today and it's still raining, but I keep it away from the rain. I take it out in the car and it's a little wet on the surface and the back of the case, so I dry it and it works good as new.

I'm not sure if these two things are related, but I decided to turn my phone off so I wouldn't be tempted to use it since it was at 6%. It's working COMPLETELY FINE, nothing's wrong with it. I was able to use multiple apps without any problem. After I tried to turn it on, I realized that the white screen with the Apple logo was on and stayed there. So I just pressed the Home and Power button simultaneously and tried to turn it on, but it wouldn't turn on. I figured it was because my phone had died, so once I got home, I tried to charge it on my computer but that usually takes a while so I used my portable battery charger since I couldn't find my adapter at the moment. When I did, I switched it to the outlet and suddenly the little battery came up, indicating that my phone was charging. But then it went away and when I tried to press the Home button, it wouldn't appear.

I realized that my USB cord was broken after I tried to charge my iPad with it and it stated "Not Charging" so I'm using a different USB cord and the little battery came up again, only to do the same thing. I really doubt that my phone has any water damage but is that what it is?

Why won't my phone turn on or charge?