You may discover very different, unique sources. Look in every nook, consider every possibility. It can be an interesting investigation into the workings of your mind. It would be boring if we had no stresses and challenges. Some people even make trouble for themselves to keep from getting bored.
Stress is a source of energy that can be directed towards useful purposes.
Mild to moderate anxiety makes us more perceptive and more productive, e.g. get better grades or be more attentive to our loved ones. By facing stresses and solving problems in the past, we have learned skills and are better prepared to handle future difficulties. A third group didn't see it at all. There were repressors and sensitizers in all three groups. The sensitizers were quite anxious if they hadn't seen the film, but the more they saw it the less stressed they became.