Addictions come in many forms and fashions. We as humans can become addicted to almost anything like gambling, alcohol, drugs, sex, food, money, success, and more. Addicts report that they know what they are doing is either wrong or unhealthy, yet they maintain an overbearing urge to continue the behavior.
This is a good starting point to assess if your behavior is an addiction or not. In other words, take gambling, if you think that it is wrong (or even if you don't), do you have a urge or craving for the activity? Is this activity interfering with your daily life? Do you continue to gamble if you lose money? Has gambling caused problems in your interpersonal relationships? If you answer yes to a few of these questions and continue to gamble anyway regardless of the consequences, you are probably addicted to the activity.
I would encourage you to seek out help in your community to help you address this situation.