Grid line on the bottom half of my phone screen

So, I have an iPhone 5C. I was using it in the rain, and I figured it would be fine because I had an umbrella, but the rain ended up damaging my phone. For the most part, everything's fine and the screen is normal, except there's a line of square on the bottom half (at first there were two, now just one). Does anyone have any advice? I tried restarting my phone, didn't work, and I've also tried setting it in a pile of instant oatmeal (I don't have any rice or silica gel, I heard that was the next best option). Thanks in advance!