The wife holds divorce over my head whenever I object to something she says or does.
So take her threat away. Agree with her. "You are right we need to get divorced. You are terribly unhappy and I have decided I am not going to be treated like this."
And mean it.
M22,H45,W45 S21/18D12 Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.