It does not matter whether your brother is insecure or not; you need to look to your own future and what you want. It does not sound like you agree with what your brother says and know him to be wrong and in trouble, what with no job and supposed to be acting responsibly as a father. It could be he reminds you of your father, being the "next" person in that line. He is not your father and not any wiser or more experienced than you are, being only 2 years older than you. I would pay attention to your mother who has been around and seen/done more than your brother, if you are going to take anyone's advice or feel good or bad about yourself just from someone else's say-so?

I would go to college and see if you can meet other guys like you and get an apartment together with them or at least hang with them instead of being around your brother and his ignorance? Just say something like, "What do you know? You're only 2 years older than I am!" and walk away from him when he has an opinion you don't agree with.