The first step in creating a sense of self in manhood is to examine the environment in which you were raised, as objectively as you can. Using violence or threats against friends or family to "show your authority" is unhealthy and damaging. Dozens of philosophies and world cultures affirm that violence is only acceptable as a means of protection from immanent danger.

You learn to internalize and suppress emotions which then fester and escape in undesirable ways. Focus on being tough to the extent that you can be a reliable, strong figure who can handle adversity. Sometimes you must do unpleasant things for the sake of the people you care for, and this requires toughness, but finds healthy ways to vent as well.

Your body changed from that of a boy to that of a man, and so should your mind and heart. Understand that this process will differ dramatically from man to man, and will continue throughout your life. The important thing is that you learn and mature as time goes on.

The main difference between a man and a boy, and adult and a child, is that men are responsible. Men know that anyone can father a baby but only a man who understands and accepts responsibility can be a good father. The difference between a man and a boy is that a man steps up to the plate, while a boy hesitates or complains.

Surround yourself with good role models, even if they're younger than you are.
Be a good man. Never stop trying to do the right thing and re-evaluate your character and integrity. If you're going to be a man, be a good man, or else it's no better than remaining a boy.