1. Don't take such small things to heart.
2. She was deserted by her lover, and in despair she took her own life.
3. He is a gloomy person, who always holds a pessimistic view towards things.
4. Why are you so pessimistic? While there is life, there is hope.
5. He took things too hard, and ended his life by hanging himself at home.
6. He hasn't come round yet. Could you try and straighten him out?