My friend died suddenly

This could potentiallylly be a long question so please bear with me. I lost a close friend about a year and a 1/2 ago. She suffered from addiction to meth which I only found out about shortly before her death. I found a pipe and confronted her, so I can only assume it was smoked rather than injected. A few days before she died she revealed to me an infection in her stomach region. It appeared to be a hole that was black and greenish that had grown larger and larger by that day. She went to the hosptial to seek treatment, (only after I pushed), and left the hosptial before being released because her blood pressue was to high and they threatened to admit her. Days later she was found dead in her home. Her family has been very secretive about the cause of death after the toxigology report was released. They told everyone it was “listed” as a heart attack. She was only 24!!! What 24 yr. old has a massive heart attack?? None of this seems logical to me. As time has passed I have wondered if she died of some sort of “mersa” infection, meth overdose, or a combination. I am so lost and miss my friend. I just wish I knew why she died. It has later occured to me that the spot on her stomach could be due to her injecting the meth. I’m just not sure. I’m not a drug user and am so unfamiliar with how things work. I miss her everyday and just wish I knew why she is gone. They found her in bed and it looked as though she passed in her sleep. Do meth users usually just go to sleep after “using” enough to kill themselves? I figured she’d have been bouncing off the walls and then just collapsed… Not settled in for a good nights sleep! Please help!