If something works, do more of it. If it doesn't work, do something else.
Everything occurs in a context:
Problems feel 'universal', as if they were 'always there'. Find exceptions: they are the clue to ways of fighting back.
Imagine you're advising someone else -- cousin, neighbour, colleague -- with this problem. What will you suggest?
Keep a problem diary. You may be tracking an action (yelling at my kids), a thought (I want to light up a cigarette), an emotion (fear, worry, depression). All of these are 'behaviors' though other people can't see them. The behavior may be something specific, or one of a class of things, eg., any thought that makes you crash back into grieving.
Keeping a diary is in itself a behavior change agent. Sometimes, it is the only action necessary to eliminate a bad habit. It is a source of information allowing you to plan an attack on the distressing problem. And it makes you into an observer, so that you can distance yourself from unwanted emotions.
In fact, all the techniques listed here help by making the problem less pressing and immediate.