Coping with addiction?

I have been raising my sisters kids since both were born. I am young and this is not how I pictured my life but I wouldn’t trade my babies for the world. My sister has no interest in being a mom except when it makes her look good. She’s still in active addiction shows up maybe once a month for what’s suppose to be a 2 day visit then stays for a week. I fuckin hate it. I have grown a true hatred for her. The damage she is doing to the kids. The anger she fills me with. I know this next sentence makes me a horrible person but I wake up every day hoping she ODed so we can have some normalcy to our lives. I refuse to fight with her whiles she’s her so I let mom supervise visitation and I either stay in my room or stay gone while she’s here which is wrong I know but I don’t want the kids around the fighting and I miss them terribly when she’s here. I can’t say or do anything with out her popping off “this is temporary” well my idea of temporary ain’t 3 damn years. Is anyone else raising kids of a sibling or have experience with addiction ? I am desperately looking for advice