I believe a negative pattern of worry is established in childhood, based upon life circumstances, experiences, and perceptions. So, in order to find a way out, you need to be able to backtrack along your way in, to where worry started in the first place.
Anxiety has written a script where you play the part of a frazzled, anxious, suspicious, irritable, short-tempered, and easily frustrated person. How do you want to be perceived by the other players on stage? When you take control of your own script, you determine the part you are going to play and then you act accordingly.
Anger is a natural emotion, but it is harmful when it becomes our focus or a continual part of our personality. Some anger is obvious, but there is also an inordinate amount of hidden anger lurking in the hearts, souls, and spirits of people.
Sadly, many of us grow into adulthood with a list of childhood truths that can include many false and incomplete truths. Families, for good or ill, give us our first lessons about ourselves.
Imagine being involved in a terrifying incident where you were physically harmed or threatened. Then imagine reliving that awful memory over and over again, each time as fresh and horrific as when it happened. This is the essence of PTSD.
In overcoming depression, one of the main areas you may need to change is the way you view life. For example, if you believe that life consistently treats you unfairly, then the inevitable ups and downs of life are filtered through that perception.