I believe point 4 can best contribute towards improving the situation in the long term. Absorbing oneself into some particular type of work that can also improve some aspect of one's life situation is probably the best. This could either be a productive hobby of some sort (side business, personal finance, volunteering, etc) or by taking on more responsibilities at one's regular job, assuming the source of anxiety is not work overload.

Another related thing that can help is physical exercise. An hour at the gym will definitely redirect resources from the otherwise constant worrying. It may also improve ones confidence and, indirectly, success in other areas of life.