"Why is my phone glitching?"に関する回答sounds like you damaged your digitizer (the thing that tells the phone where you touch) I would recommend replacing the screen. You could take it to a repair shop or use this guide to help you.
"My screen has been cracked from the inside"に関する回答Hate to say it, but you’re most likely going to have to replace the screen; if you arnt’t up for a challenge, you could take it to a tech repair shop, or you could follow the instructions found here. Heads up, this repair is pretty difficult, and might be out of your reach.
"iPhone 5c has no power."に関する回答It could be the charging port has shorted I would recommend plugging it in when you receive it though as occasionally these sorts of problems fix themsleves