The crucial time is just after you have completed the task. Let me give you an example. Imagine that you are struggling to get out of the house and you set yourself a goal of walking round the block. You have worked yourself up for this and you have achieved your goal and you return to the house. You might imagine that there would be a sudden sense of achievement and release of feel-good endorphins. However, often the exact opposite occurs. The voice of depression is likely to kick in to try and discourage you by undermining your achievement. After all, it doesn't want you to start getting any ideas. As a result, you will normally get the:
'How far did you walk? 400 yards? Is that all?
'If you can't walk further than that, how are you ever going to lead a proper life?'
'You might as well stay in bed, if that's the best you can do.'
You need to be kind to yourself. You need to congratulate yourself for what you have done and you need to try and keep the voice out.
SAY NO TO THE VOICE.