I'm doing my best to capture how bad the experience is and I don't object at all to anyone suggesting that it's worse than I described. I think it's a very bad system.
There's a reason I said it doesn't have to be a medical person. I'm in the same boat - I had the worst experience of my life when I spoke to authorities about a suicidal episode. It was degrading and dehumanising. I will never make that mistake again, if I'm feeling suicidal I will never tell authorities, a doctor or anyone who might put me in that situation again.
That sucks, and, having some little bit of knowledge about the process you went through, I absolutely believe you.
Having said that: if you were my friend, and you told me you felt like you weren't in control of your thoughts and were concerned you might harm yourself, and you had no better options lined up (a long term mental health expert you'd built a relationship with, for instance), I'd help coerce you into the emergency mental health care system before I allowed you to become a victim of a controllable illness.
The former sentence is more a statement of religious belief than an argument. The latter is demonstrably untrue. Either way: the point of my comments isn't to take the side of the mental health care system and argue with all comers. In particular, there's a reason I keep using the term emergency mental health care.
