My mom died and I feel so much guilt

My mother and I had such a strained relationship. We fought so much my entire life because I was so angry about her smoking and drinking and always felt it came before me. Then she would always say "nothing, I do is ever good enough" "i guess I'm a real oiece of s,,," and things like that.  It got very bad 3 years ago when in order to hide her drinking from people she fired my grandmothers home health and put her on hospice, shortly after my mother got very ill from the drinking and sent my grandmother to a home without telling anyone where she died within a day. I promised my gram I would never let that happen and would take care of her, but instead she died alone and I found out with a drunk call from my mother "your grandmothers dead in case yiu wanted to know."  I was moving across the country that same month and determined to find a way to get my grandfather there in the spring, however I Feb. He got ill, my mother sent him to the bad hospital where he contracted something from a third world country on top of pneumonia. Whe. I heard how bad he got I demanded he be moved, but it was too late... I got there in time for him to go to hospice. She insisted he go home on hospice and then I was left to take care of him, she sat and drank. so many awful things happened, when I got him to inpatient, she refused to visit, at the funeral she talked bad about us and went to everything with her friends instead. Somehow after the fighting, I felt sorrow that she lost both her parents and started calling her daily. She didn't leave her house other than a weekly dinner with a friend. She had a home aide that got her food and apparently also her vodka. She seemed okay, always talking about tv shows, food things and listening to my stories. I saw her at Xmas and was overcome with a feeling it would be the last time I would see her alive. I didn't do anything different, I didn't have a big talk with her, I went on as usual. At the end, whe. I talked to her in the hospital, she wouldn't say I love you. I got there only 9 hours before she died. I so wish I got there when she was alert, to make her feel loved as I know my brother was only pushing a will in her face and although he tried to be loving in his way,  she had to be so upset by that. I not only wish I could've told her i loved her anyways and appreciated the things that she was able to do for us, but I'd do anything to know if she had any real love for me, if she understood how hard I tried even though sometimes I came off mean. Everything she said seemed to be a lie or attempt to hide the truth. she complained that I was a b***h to my brother a lot, when I was the only one who showed up for a holiday for 15 years. The again, I'd never stayed at her house, I knew it hurt her, but the house was dirty and my brother told me it was haunted and just couldn't stay there, I  should've stayed to make her happy.  I found a beautiful card she got my brother and never gave him, but nothing for me. I always had the glimmer of hope for that mother daughter relationship, wedding dress shopping with her and silly things. I even told her that dream in tears once, now I'll not only never have it. I wanted the best for her, I wanted her to LIVE, she had so many talents all thrown away....but she probably died thinking her daughter hated her and she had to answer that phone every day to appease me. Had I been more compassionate things would feel so different today.