Oldman1 --
Sorry to say, we often are disappointed and disillusioned by what people do to each other, especially to those whom they are supposed to love. Spend an hour on these message boards and anyone will come away feeling those same sad emotions.
I hear you and I welcome you to MB. You've come to a very good place and we'll help you all we can to get through this pain. All of us here--and it's thousands of us--are hurting from the pain of betrayal and disillusion. You've joined the ranks of fellow sufferers and 'twas a smart move.
First, the OMW and her attempted suicide is not your fault and not your responsibility; you can't control another person's actions. I agree that it would be a terrible waste if she would follow through but it's not your doing or your obligation. Sometimes a threat like this is a plea for help, other times it's a manipulative power play on her part. Either way, you're not responsible.
Next, you seem to have a good hold on yourself and a healthy perspective on things. I'm thankful that you see clearly what is going on. Of course you're right that your W's reputation will suffer but I suspect that's the farthest thing from her mind right now. That's her problem and her albatross but it becomes yours by extension as you have teenagers to respond to and family and your friends.
She "doesn't seem to care" because, for now, she selfishly doesn't care about anything or anybody else but herself. That's what The Fog does to people, how it affects them, clouds their judgment and decency, and creates pain and havoc across the board. She cares about the OM too, but don't bet the farm that that mind-set is a given. A two-year A is a long one, but not unheard of, and certainly nothing compared with your 19-year marriage (and the OM's 36-year union). You can't see around the corner, and while I don't want to give you false hope (assuming you want to preserve your M), I would say that the final word isn't in yet.
Please hang in there. Post again and let us know how you're doing. We're here for you...
Ammon