B) My headache is killing me. It is not literally killing him, it is an exaggerated statement.
Gloomy. The way which the character describes his cell makes it seem like a dark and gloomy place. He said they gave him a blanket and a toilet and thats it, the bars are rusty, the cell was crumbled. The guard even smiled at him as if he was enjoying putting him in there.
Hope this helped. Have a great day!
Actually venting problems with the person may help them understand that you dont like or wont tolerate his or her behavior and can help understand not to do it in the future with other peers. It's never good to be shy and scared please speak up.