Why would I not show him I’m crumbling?

I am going through a split (kids are involved) and it was his doing. Everyone around me is saying don’t show him I’m crumbling and a mess. But why?

Don’t you think showing him how much I love and miss him will make him see how important it is and how we need to be together were a family.

Why would it be wrong to show him my emotions.

Although when I call him crying saying how could you do this to us he literally says nothing!!