If she was threatening to leave you, isn't that synonymous with threatening divorce?
It may be a helpful reminder that a woman cannot divorce her husband, she can only leave.
To clarify, in a marriage from the state, she can "divorce", but from the biblical view, a real marriage, she can't. Any passage mentioning a woman divorcing is either a liberty taken in translation, or addressed to a culture where marriages involved the state. Because state "divorce" and a woman leaving are often concurrent, the concepts can get conflated.
Think of how we might refer to a branch being cut off – it's from the perspective of the tree (the body). We say, "that branch is cut off of the tree" not, "that tree is cut off from it's branch".
A cut branch can be grafted back in, but we do not graft trees back to branches, that's the wrong perspective.
The same could be said for a member of your body. The hand does not send it's body away in divorce, the body sends it's hand away.
Of course a woman can walk away of her own accord, but that's not divorce. If you label that as divorce, prepare for a lot of confusion in your study of the Bible. Biblical divorce is only when a man sends away a woman.
If she walks away, that is a lot more painful than divorce, because having your hand ripped from your body by outside forces is much more violent and shocking than deliberately anesthetizing, stabilizing, and amputating an infected/corrupted limb.
A violent removal is what is at risk here and that is why fighting back is in order, you have a right to self-defense of your own flesh.
This is why your brothers here want to help.