The best definition I’ve read somewhere was along the lines: addiction is something you do repeatedly even though you know it’s harmful for you.
This makes it sound like you trying to say addiction is a mental thing. When your body is physically addicted so that you are sick and in pain because you didn't dose, that's not mental. At that point, it could be more harmful to not fix regardless if you know it or not.
There are so many behaviors that fit that description that few would count as addiction. For example eating sweets or junk food, procrastinating, not drinking enough.