my best friend was alcohol dependent and died recently in a very horrible and undignified way. She left two children behind. She neve acknowleged that she had a problem and i fiercely protected her reputation and didnt know how to deal with the lies and sometimes manipulation. Its left me feeling conflicted. If she had admitted and accepted help she could have had a chance to see her kids grow up. Im not angry but some of her other friends are and blame her ex partner for her death - which is wrong on every level.
I’m very sorry for your loss. Addiction is an illness, your friend was powerless to it, and sounds like she was in denial about it. It was her way to feel ok. You’re right, it makes no sense for others to blame her and being angry at her as she was clearly struggling hence why she drank. It’s very sad too that her partner is being blamed, as if the loss isn’t enough to deal with. The people around a loved one in addiction are powerless too, the only way is for the alcoholic to acknowledge the problem and seek treatment and recovery. No one else can change that or do that for them. I understand you feeling very protective of your friend. My ex boyfriend was an alcoholic and he died less than 5 months after we broke up. Of course I blame myself. He had been in rehab last year, then relapsed. He was weeks away from getting back into treatment when he died. It’s horrendous. I hope you can get some support and your friends partner too. 
Bereavement counselling might help. Im in Scotland and have access to bereavement counselling through Scottish Families Affected by drugs and alcohol. I wonder if there’s something in your area? Take care.