Masturbation is just another form of sex. Don't worry about it. Almost every sexually addicted person uses compulsive masturbation. For some sexually addicted people masturbation is their main form of sexually addictive behavior. For others it is a substitute for their preferred sexually addictive behavior.
Masturbation can definitely become an addiction.
The problem is getting people to engage in a rational discussion about it. Most people discover masturbation in puberty. Some don't discover it until their early adulthood. The defenders of masturbation propose advice that is as foolish as the attacks against masturbation. The defenders of masturbation refuse to admit that masturbation can become an addiction.