This is a tough one. I've had 6 addictions in my life: Weed, Sex, Games, Alcohol, Gambling, and the Gym.

They started out as behaviors that made me happy. Then I continued to do them repetitively until I was exhausted. The behavior continued because mentally I felt awesome. The illness began when my brain couldn't live without these addictions. I would end up having anxiety attacks unless I performed the act.