Ways to challenge negative thinking:

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•  Prayer. Anytime you start having thoughts of failure, regret, I cant, get on your knees and pray, you could start with some praise and worship, it works!
• Think outside yourself. Ask yourself if you’d say what you’re thinking about yourself to someone else. If not, stop being so hard on yourself. Think about less harsh statements that offer more realistic descriptions.
• Allow yourself to be less than perfect. Many depressed people are perfectionists, holding themselves to impossibly high standards and then beating themselves up when they fail to meet them. Battle this source of self-imposed stress by challenging your negative ways of thinking
• Socialize with positive people. Notice how people who always look on the bright side deal with challenges, even minor ones, like not being able to find a parking space. Then consider how you would react in the same situation. Even if you have to pretend, try to adopt their optimism and persistence in the face of difficulty.
• Keep a “negative thought log." Whenever you experience a negative thought, jot down the thought and what triggered it in a notebook. Review your log when you’re in a good mood. Consider if the negativity was truly warranted. Ask yourself if there’s another way to view the situation. For example, let’s say your boyfriend was short with you and you automatically assumed that the relationship was in trouble. It's possible, though, he’s just having a bad day.

 Philippians 4:8 ESV

Finally, brothers, whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is lovely, whatever is commendable, if there is any excellence, if there is anything worthy of praise, think about these things