What is wrong with my iphone?

I have an iphone 5c, never had any issues and haven't dropped the phone. One day o had a black halo circle at the bottom right corner of my phone. Stayed that way for a few weeks until the screen just went completely black even when the phone was actually on. Now I'm able to see a partial area of my screen with the rest being covered in lines. What is wrong with my phone? How can it be repaired and about how much would it cost? What is wrong with my iphone

App won't delete from iPhone?

I have an app that will not delete!

I updated to iOS 10 to try to get it to delete, it didn't.
I logged out then back into iTunes. Didn't work.
I tried simply deleting, didn't work.
I tried rebooting the phone. Didn't work.
I tried reinstalling the app. Didn't work.

Has my iPhone been hacked

Today, my boss confronted me about some text sent to her and it looked like it was some search history of mine and on my end of my iPhone it doesn't show that I sent anything but on her receiving end, she got some big bulk text message about random things coming from my number! What could have caused this? I was just listening to music which I'm allowed to at work because it helps me focus and I had my iPhone in my pocket. Could i have hit something by accident and sent it? Or is this a hacker? Please answer. Serious answers please.