People deserve to have their experiences understood in a genuine bio-psycho-social approach. All too often, this is ignored in favor of what is a very reductionist, bio-medical, model.
I believe that mental health services should be based on the premise that the origins of distress are largely social.
Maintain your relationships - for all kinds of reasons, friends are vital. Good friends, supportive friends, friends who won't judge you or try to take advantage of you.
When you notice an unhelpful emotion or a shift in mood, or when you notice that you're doing something you know can cause problems (being snappy, for example, or drinking too much), that could act as a cue to examine your own thoughts - "what am I thinking?".
Rumination tends to be eased if we learn to be mindful; if we are able to be aware of, and understand how our own thoughts work.
Keep your brain active. Engage your brain. Your brain is the most fantastic machine ever created, and it needs to be exercised.
There's real evidence that getting involved in charitable activity (and it's probably better to give your time and effort, rather than money) makes people happier.
I think, in all honesty, the first place that someone in emotional distress should turn is their loved ones, and then to use professionals.
Keep active - do something physical each day. Could be as simple as taking the dog out for a walk (if you've got a dog!), but could be going for a swim, or going to the gym every day.
When people are in acute crisis, residential care may be needed, but this should not be seen as a medical issue.
Many people are probably better off avoiding therapists and using the resources and support available to us in everyday life. But therapy can be a chance to think things through with a professional in a calm, supportive and nonjudgmental atmosphere, and that can be helpful.
