My dude. Low blows. I proposed finding professional help, and a safe person to help ops partner. Not throwing them in the deep end. But you seem to ignore or reframe mostly everything I said. I get this is a hard truth for you to face.
It's not one untrained person's responsibility to fix another person and without training and proper knowledge you could be furthering the problem, that means making it worse. For both people.
Yes it's important op leave without contact, once mental health care has been sourced. If possible. Because ops partner won't be able to rewire their brain without a clean cut. As there's severe enmeshment here. You are proposing op stay and help ops partner, regardless of how they're feeling or coping. Because you did it.
This relationship description is called codependency. Sometimes the person being depended on comes to define their self worth, entirely, by being so important to the other person.... But It can also cause severe harm to the person being depended on.
I get that these are really hard truths for you to face, but that situation wasn't healthy. And you skating through, doesn't translate that everyone should face a situation like this in exactly the same way you did. You were doing the best you could at that time. You can't change the past, but we can learn and grow, when we notice mistakes. That's wisdom, my buddy.
You're basing your opinion on this situation, entirely on your own past experiences, but your opinion doesn't align with current and past understandings of the definitons of abuse, or ways to handle someone feeling suicidal or enmeshment and codependency. I hope you are able to still feel proud of the fact your intentions in your past relationship were kind, and you did the best you could with the knowledge you had at the time, and learn and grow with more knowledge. I was going to link some articles for you. But this is your journey to choose to take, or not. I'm going to let you find that pathway for yourself. And if you don't choose that journey, I hope we can just agree to disagree.