My brother passed

My older brother at the ripe young age of 39 died on November 18th 2022, leaving behind two kids; my niece and nephew. My brother was a difficult person, and I had distanced myself from him to keep my own inner peace. He lied and he stole, he was on drugs like anything he could get his hands on he would try. He would get better for a little bit and start getting his life together and then it felt like something would switch in him and he'd be back on drugs again. It seemed like he just was capable of dealing with life unless he was high. The most infamous story I have about him involves him telling his kindergarten teacher that our mom had died, and his step dad (my real dad) made him go to school anyway. This was of course false, our mother is still alive to this day. This was just a drop in the bucket, or ocean really, of all the lies he's told over his lifetime. I often wondered if he even knew he was doing it anymore, maybe he'd lied so much he made himself start believing the crap that would come out of his mouth. He told me once that his cousin passed away and that the US army flew him, his girlfriend and two kids to Hawaii for the funeral. I'm his sister. We have no cousins in the army or any branch of military for that matter. I could keep going but I won't waste anymore of anyone's time on that.
I'm unsettled by his passing. Most days I can go all day without thinking about him. We weren't close, he knew I didn't want anything to do with him, I can't even recall a happy memory I have with him. Every so often I find myself crying over him and while I do I'm asking myself why, why am I upset? I knew what he was, I'm a recovered addict myself so I know what happens to people who go down the path that my brother lived on. This wasn't unexpected, so why can't I move past it.
My brother was found in my dad's house by our younger brother. Older brother had recently moved in after being asked to leave his biological father's house, my dad, who raised my older brother, said he could come live with him. I told him it was a mistake, I told my dad if he needed to bring things to my house to hide from him he could. I was honestly expecting a call that my brother had been taken to jail, not a call from my dad telling me he was dead. I rushed to my father's house so fast I don't even remember driving there. But I remember the frown the cop gave me when I asked if he was dead. I remember my mother's face as my dad pulled up to the house with her in his car. I remember the sounds that came from our grandmother after me and my dad told her the unfortunate news. And I remember the bloodied bedsheets I cleaned up so my dad wouldn't have to clean up the blood of his own child, biological or not, he was my dad's child.
Losing him was awful, one of the worst days of my life for sure. But learning days later where the drugs that took his life came from hurt so much worse. Our aunt, my dad's sister is who used to sell me the drugs I was addicted to. And after getting my brother's cell phone working we found through their text messages that the fentanyl had come from her. A person who was there when I was born, held us as babies, helped raise us. That's who helped my brother end his life.
I can already hear people saying 'she didn't force him to take it' or 'he would have just got it from somewhere else if not from her'. She was our aunt, our family, someone we've known since birth. All she had to do was say no. Let him get it from someone else, let him find another avenue to get his fix. She had every opportunity to just tell him no and she chose not to. I don't entirely blame her, but I sure as hell lay some of the blame on her.