I'm Bipolar 2 and more often depressed than hypo-manic (as is typically the case with people who have bipolar disorder). When I get down I can fall into a pattern of
automatic thoughts, where I tell myself things like, "that was so stupid, why did you say that?, you're such a klutz" and so on. Another trap me and other people with depression, anxiety and related disorders fall into is
Cognitive Distortions. Common cognitive distortions include:
Overgeneralization: You see a single negative event as a never-ending pattern of defeat.
Disqualifying the positive: You reject positive experiences by insisting they "don't count" for some reason or other. You maintain a negative belief that is contradicted by your everyday experiences.
Emotional reasoning: You assume that your negative emotions necessarily reflect the way things really are: "I feel it, therefore it must be true."
Should statements: You try to motivate yourself with shoulds and shouldn'ts, as if you had to be whipped and punished before you could be expected to do anything. "Musts" and "oughts" are also offenders. The emotional consequence is guilt. When you direct should statements toward others, you feel anger, frustration, and resentment.Full list at:
http://healthymind.com/s-distortions.html It's helpful if you can begin to recognize these common mistakes in thinking as they're happening and then stop yourself as they occur. For example, if you find yourself thinking "I'm doing really bad at work", stop the thought immediately (a process known as "thought stopping"). Then purposely think of what you are doing
well at work (e.g., you got a particular assignment done before the deadline or came up with a more efficient way to get a task done). You may find that you aren't really doing bad at work overall, but are merely noticing only the bad things rather than the good (#3, Mental Filter). It's not easy by any means, but it helps.
Cognitive Behavior Therapy can also be immensely helpful. You
can learn the techniques from a book, such as
The Feeling Good Handbook by David Burns. However CBT is rather structured so learning it from a therapist is often better for many people. Fortunately it is not a lengthy process like some other forms of therapy so the expense is less of a concern.
Best wishes, and if you have any questions let me know. I'm always glad to help if I can.