You are right. You haven’t lived. Your grandfather is still in control of your life because you haven’t found a way to metabolize the traumatic experiences of your childhood. It sounds to me like you internalized his messages to the point that you have no confidence or even respect for yourself. I want you to know that this is not an unusual reaction to being traumatized repeatedly. All the symptoms you described, including the emotional dreams, are consistent with a diagnosis of Post Traumatic Stress Disorder (PTSD).
As you already do know, you can’t drink or drug this away. Isolating yourself doesn’t get the pain out. In fact, it only helps to lock it up inside you. You need therapy from a therapist who has experience working with repeated trauma. As frightening as it may seem to dig deeply into your issues and talk about them, I don’t think it will be any more painful than what you’ve been doing. Further, the pain of going through it is what will get it out. You will then be helped to build your severely damaged self-esteem as well as your coping skills for managing stress.
With some changes toward a more healthy way of living and therapy to change your self-esteem, you have every reason to believe you have a good 50 or more years of life to live. With a real effort in therapy, you can look forward to having a successful life that includes good friends, good work and perhaps a good partner. I hope you will find the courage to do your therapeutic work. You deserve it.
I wish you well.