Eating Someone(bothering or worrying someone)
Hey, Alice. What's been eating you lately? Don't you realize how rude and irritable you've become?
I know. I'm really sorry for the way I've been acting.
Well, why don't you tell me what has been bothering and upsetting you and maybe we can work your problem out together.
I'll admit that it would help to talk to someone about it.
work out = 解決する