Sometimes when I'm depressed, everything becomes negatively self-centered.
I'm occasionally not very good at dealing with failure anyway, but when I'm depressed, every single thing I fail to do or do incorrectly becomes a generalized internal statement about how rotten I am.
"I don't know the answer to that question" turns into "I'm so stupid."
"I phrased that wrong" turns into "I never do anything right."
Even things that are entirely outside my control, like my level of arthritis pain, reflect back on me and who I am. "My arthritis is really bad today" ends up turning into "I'm useless and can't do anything."
When I'm depressed, if someone disagrees with me, I may just burst into tears and freak them out, because a part of me hears "Actually, I like this movie better" as "You're a stupid idiot for having that opinion."
That's hard to combat. Either I have to make every single decision and perform every task perfectly every time so I receive nothing but praise (which, HA, is never going to happen, because nobody can do that) or I have to find a way of combating the bad thoughts.
Remembering past praise is one way I try to do this. I don't remember if I've shared this before on this blog, but I have a big ol' Word document on my computer where I have written down pretty much every positive, encouraging thing someone has said about me in the past 5-6 years. I read through that document on a pretty frequent basis. It really helps to see page after page of affirmation, of encouragement, of compliments, because while I may not believe any of them individually at the time, several pages of positivity can help to at least balance out, if not entirely counteract, the negativity in my head.
And sometimes I'll just come right out and ask for people to combat that. Every couple months it's not surprising at all to see a Facebook status from me saying, "Having a weird day. I could really use some positive words of affirmation and encouragement. Thanks."
But sometimes I just have wait it out and continue to tell myself, "That's not true. You're not stupid. You're not worthless. That's just the depression talking. You will feel better eventually. Just get through it."
And, eventually, I do.