My ex-girlfriend admitted, yesterday, that she's a lier and a thief. I dislike being cryptic, but don't want to discuss detail.

I'm happy, but sad. When i smile, i break inside. When i cry, i laugh inside. I don't know what to be. I don't know what you want, nor what i want. I don't know the difference. I should probably be listening to the teacher guy right now. I can smile all day, but night becomes my hell. Is it normal to have 'happy juice', that runs out after a while? Or, at the same time, 'unhappy juice', that takes over, but can be overcome if the urgency is sufficient enough?