Derek had really dug a hole for himself, hadn't he? Why did he have to have such a terrible personality that the one he loved genuinely thought he was always annoyed with her and that she didn't do anything for him?!
Any time she did drive him crazy was either because she was making herself suffer unnecessarily or because his own stupid feelings were getting in the way. That much wasn't on her.
He was having a hard time getting his thoughts together to set her straight without letting her know he was in love with her since she was still hugging him. Pathetic.
It took him a minute to come up with something. "Well, you're the only person who genuinely wants me around for one thing. You're always there to cheer me up or calm me down and put up with my crap better than anyone else. And you make me lunches and stuff when you totally don't have to."