no you did not fail yourself. you are living in a neglectful abusive environment and doing what you can to survive. please do not give into that destructive craving to do heroin. it sounds like you have the survival skills to make much of your life once you are able to get out on your own as long as you dont get caught up in that scene. you need therapy to get over the trauma of your life. can you go to your school counselor and talk about all this so that you can get some help now?