“Depression” in a medical context is not something that simply goes away. The cause is not a stressor such as exams. It is an unnatural imbalance of chemicals in your brain. This can only be treated by medication, or you can mask and adapt to learn to live with it.
I’m sure stressors can trigger episodes of more severe symptoms but one does not simply “problem solve” away depression.
This is not to say you have medical depression. However, if you notice this feeling does not go away, it may be time to consult your doctor as this is no replacement for medical advice.