I'm sorry for your loss. I'm not a medical practitioner but it sounds like the experience triggered a psychotic "break" in your friend? It's a sad but real possibility with psychedelics that more people should be aware of.
Whereas in other groups a cascade effect sometimes happens and many people in such groups can experience mental health issues, and trauma.
There's that common call to examine "set and setting" but it's often a crap-shoot, due to the chaotic number of variables.
Her suicide is very sad but I can relate. Rest in peace.
Personally it took me at least a month to feel functional again and then probably a year to start feeling better. Prior to that I struggled immensely with depression most of my life and abusing substances was my attempt to pull out of it, so to bottom out intensely like that feels extremely hopeless.
Once again giant disclaimer that I’m not authority, but I learned more about how psychedelics work from neuroscientists who research them and it was very illuminating. They are extremely potent in regards to neuroplasticity which seems like why they can be heaven or hell (https://en.wikipedia.org/wiki/Psychoplastogen). My best take away from the scientists was to space trips out by several months similar to what you should do for MDMA. Frequently redosing keeps your brain activity from stabilizing. That’s not their advice or strong statements (they were avoiding advice-giving entirely), of course, just what I took away.
Years later and I have done a lot introspection and learning and I have taken psychedelics again. I can identify my own anxiety, paranoia, or bad patterned thoughts creeping up and talk myself back. I don’t attribute that traumatic experience or drug use in general to improving my circumstance and I sure as hell don’t recommend it but it does seem like my life going to total shit was a step I needed to take to get it back together. Therapy would’ve been easier.
Had a similar experience to you but took it in a different way. Came down out of the craziness and realized "hey, I'm still here, shit could be a lot worse"
But I don't get why you still came back to them after having a negative reaction. Seems like a good sign to stop