I've actually been feeling pretty good for the past 10 days, and this morning I filled out a depression questionnaire for fun and scored 2/80. Great, right?

Fast forward to this evening and someone's insulted me and given me pause for thought about the career path I've chosen, and suddenly I'm idealizing suicide - "it's all hopeless anyway," "things are never going to get better," "I'm so fucking lonely and sad [despite being fine this morning]." 

If you do this, how do you cope? I find it frustrating that my moods and life outlook can be completely upended at relatively small provocations.