There is no reason to be afraid of masturbating. It is a perfectly normal and natural thing to do. It helps you relax and relieves tension. It helps you learn about your body and become more sexually responsive. It is not the same as sex with a partner.
Masturbation is just one form of sexual expression.
Sex with a partner involves many more emotions and sensations, and is a totally different experience. I'm not going to tell you what either feels like because that is impossible to do. Sex is different for everyone. Maturation does not cause addiction, dysfunctional sexual behavior, or other bodily harm. Most people do not become addicted to masturbation.