I believe every adult has a preconceived idea about what “should happen” as they progress though this thing called life. At some point, and that point is likely different for everyone, we come to acquire expectations for the future. The net difference between our expectations for the present and the reality of the present is how I measure depression and anxiety. If the situation in question resides in the future, or if you feel your self-talk “spinning” on something forthcoming, then anxiety is the penchant of your present feeling. If you linger on the past, your history, what could have been… then depression is probably your poison of choice. What is the secret to not being depressed or anxious you ask? Live in the moment. If, even for one moment, you find yourself able to let go of the past and not worry about the future ~ you will almost certainly find peace. If you can do it once, you can do it again. If you pursue the combination of thought, feeling, and action that produces a persistent state of present mindedness ~ you will almost certainly reach whatever goals you set.
I love that Carmax commercial that purveys a place to start. If you were going to start looking for a car, they think the best place to start is their car-lot because you can test drive every make and model before you make a decision. Now, if you were going to start on your own mental health, where would you choose to start?