@skp,
You are 16, right? Almost 17.
Begin to be your own man. Do not listen to others who drag you down. You said they do drugs and have been abusive to you. Why would they have any good perspective of life or of you?
You have said that you screwed up when you were young. No more excuses. You are responsible for what you do now. So don't do something stupid.
You sound like you want to do better. Is there ANY adult you can talk to (priest, teacher, friend, relative) that will help you through these years?
Good luck! We care here.