Marijuana is, in fact, addictive. Depending on what study you look at, roughly 10%-30% of people get addicted to marijuana. (Link is good for other information about the good and bad of marijuana.) The behavior and routine is definitely addictive too. People who smoke tobacco definitely have the same problem.

OP, rather than smoking if you are actually using it for medical purposes, try baking it into food. That way you still get the medical benefits, but there won't be smoke cause problems lungs.

OP, also note that marijuana is not good for your brain development. Most people's brains aren't fully developed until 25-years-old. If possible, get access to CDB oil and use that instead of marijuana. THC is the primary culprit for brain development problems from marijuana, and if you can cut that part out, you'll be doing yourself the most help.

Seek help from medical professionals. A therapist may be enough. You might need to get a prescription from a medical doctor for CBD oil.