It is very difficult to fix a problem until you take some ownership in it. You have written 5 paragraphs and not one time have you admitted or listed anything that you do to cause the reaction that you get from your brother, step-mother and sister. There is a reason that they interact with you the way they do. Why is it? If you permit this anger to manifest and take over your life who is going to get hurt by it?.....YOU. Why would you not want to fix it? You can't go through life blaming everyone else for your failures, actions and ineptness.
Do you want to end up "behindbars?.
Come on...start taking some ownership in your life.
You should be having a conversation with your dad, "Dad, I am having some real problems sorting out what is right and what is wrong. I know most of the relationship problems that I have with my family is my fault and I don't know what to do...would you please help me? I need counseling or something to keep this anger from continuing.
Good luck.