THe reason why waywards are sad is because they are giving up on their marriage...

To their mind the marriage isn't meeting their needs and in their head they have exhausted all useful avenues of repair.. so they are resignign themselves to a failed marriage slowly, in thier MIND... this happens gradually over the course of time... hopelessness manifests itself as sighing, frowns, pessimistic statements, negative commentary, cyncism, and general distance and uncooperative approaches to living in the marital home...

Its not you, its his choices, his respnose to his dissatisfactionw the marriage