So sorry Greg; I can relate as I’ve lost both parents in the same year, 6 months apart.
I’ve been a mental health nurse now for most of my career and it is true that once someone makes up their mind to leave, there really isn’t much we can do to prevent it. Medications, counseling of course can help but not always. And, some of the medications side effects are worse than the symptoms to the patient. Some demons cannot be defeated unfortunately. Every day they wake up and the pain, real physical pain manifests and the only way out is to end it. It’s hard to understand but it is a real thing, and anyone who tries to deny the seriousness of a mental health disorder is nothing more than a complete idiot at best.