Studies on neurocognitive processes indicate that mindfulness meditation increases awareness and the creation of alternatives to mindless, automatic behaviour, thus reducing the stress response by guiding conscious thought away from uncontrollable past or future scenarios and towards a non-attached acceptance of present circumstances, rather than battling unwanted thoughts. Because the brain has less opportunity to scenario build and apply internalized interpretations to forecast social responses, actual or perceived threats have a reduced ability to trigger feelings of anxiety, fear and lack of control.
There is a lot we can do to help ourselves. Of course, there are times when professional help is required. I have spent many years working with mental health workers, and I respect them immensely. I have also known the reality of mental illness in my own life and in the lives of others close to me. There is always help available---if you want to be helped and are prepared to go through what is sometimes referred to as the 'agony of change.' Having said that, much of the so-called 'agony' is due to our resistance to change as opposed to the change itself. The latter can happen very quickly, even instantaneously at times. In other cases---most cases---it takes time.