How bad do things need to be before seeking counselling or psychotherapy?

Sometimes the perception is that you must have a mental health disorder or be severely struggling with life in order to seek therapy. You don't. Therapy isn't about diagnosis. In fact I work with real people with real everyday issues. If something's not working for you, even if you can't put into words what's wrong, counselling could be of benefit.

Why should I discuss my problems with a stranger?

Many people find it easier to speak to someone who is not directly involved in their life or situation and who will listen without judgment or bias.