If you are suffering from anxiety or depression, one helpful tool to use is a thought record. You can find this tool on-line by googling "thought record for depression or anxiety" and many different templates will appear for you to print out.
Oftentimes, an event triggers a negative thought which in turn, triggers a negative emotion and then behaviour, resulting in us feeling lousy and down on ourselves. The thought record guides you to address these negative thoughts by finding evidence that refutes them, which in turn releases you from experiencing negative emotions and improves your overall mood / level of anxiety.
The goal is for you to train your brain to naturally start addressing and transforming negative thoughts into more realistic, evidence-based thoughts that help to improve how you feel! For best results, this should be done several times each day until your brain is retrained!