Cocain, the story of your mom is so similar to my own mom's story I can't believe it. My mom died a little over a year ago. She spent the better part of her life on hard drugs and alcohol. Towards the end she was off the hard drugs and alcohol but still couldn't shake the presription pain killers. She simply abused her body too hard for too long. Her heart gave out at the age of 49. I wish I could could give you some good advice on how to deal with not being able to say goodbye, but I'm going through the same thing. Our relationship had been strained for about 20 years and we hardly spoke. She lived in Ely, Nevada which made the no contact thing pretty easy. The last time I spoke to her was about 3 months before her death and it was a horrible conversation. I called her up and was yelling at her because she had just told my youngest sister she was in so much pain that she was going to kill herself right after my sister's wedding (my sister was to be married in about a week at that time). It was an ugly, ugly conversation. We didn't even speak at my sister's wedding the following week.
A few months later she called my cell phone about 5 or 6 times in a few day span leaving voicemails each time stating how sorry she was, how much she loved me, and how she just wanted to be able to talk to me again. Each and every time she called, I'd send it straight to voicemail. About 1 week after those phone calls, she was found dead in her living room sitting in her recliner. My relationship with my mother was always horrible, but for the rest of my life I will regret not picking up that phone.