Mourning my dad who is still alive

Hello, I’ve never posted here but I have observered for a while. Personally I’ve been to just one non-traditional Al-Anon meeting where I was the only person to show up, and it was more of a one on one conversation with the lady who ran it. Which was fine and she was sweet but it wasn’t the support I needed so I didn’t return and haven’t tried others out of worry because I have a one year old that I have to tote around everywhere with me.

But here it goes, my Q is my father. He was a former heroin addict before i was ever born, and around the time of me being 12-13 he started drinking very heavily to self medicate his extreme bipolar and personality disorder. He was violent and abusive and it has been 10 years since then and there are permanent marks engraved into my psyche from him. I didn’t get a childhood, I had to survive, and I felt as though I had to protect my mom because she was not protecting me. I started talking to my therapist at 16 after I tried to end my life to get away from him and that’s when I found out this was not normal and he was abusive, but I was intimidated into keeping secrets so he wouldn’t get it trouble. He had guns as a convicted felon, he was a semi-truck driver, he was a “stand up guy” to the outer world. He tried to kill me when I was 15 by pointing a loaded gun at me while black out drunk, while my mom fled in her car and left me with him, not calling the police.

That is some of my backstory with him, that being said, I (23) only got out when i was almost 21 and pregnant and terrified but determined to protect myself and my unborn son. He went below rock bottom from that point when my mom finally kicked him out and started hanging out with an old friend who is a cocaine addict. Then he stole all my dogs epilepsy medicine and overdosed to try to end his life. Then came multiple stints in rehab, all unsuccessful. Then one “was” and he went to a recovery house where I knew in my bones he wasn’t sober but he just seemed odd, not drunk but not himself, but I hardly saw him. My mom started dating a new guy and there were constant death threats to her and myself. Then my son was born and he wanted to see me and him often, and something about him (on top of all the trauma he has inflicted upon me) just made my skin crawl. I ended up cutting contact with him this past July from the death threats to my mom starting again. My grandfather (his dad) called me in early October and told me he was going back to a rehab facility. He called me for the first time two weeks ago and i missed it but he left a message that he had gifts for my son. I picked them up from his girlfriend the other day and she told me he was 1. Still drinking, 2. Smoking crack, 3. Doing heroin again, and 4. Doing cocaine. When she searched her garage and found all of it she gave him the ultimatum to be homeless or go to rehab. He will be there for minimum of 6 months. I am at a total loss. I know I’m not responsible, but why do I feel responsible? Why do I not get to just have a dad, my son just have a granddad?