What you say to yourself in the first minute or so is very critical. So the little voice mastery technique for that one is the exact opposite of what you do to deal with success.
Don't attribute the problem to yourself personally.
I'm not saying you're not going to take it personally, because that's hard not to do. But what's easier to do is to say, 'Obviously, I was not aware of the other circumstances or other products that they were looking at so, while I'm responsible, it's not all because of me.'
The thing you don't want to say to yourself is, 'There's something wrong with me,' or 'I'm not cut out for this. I knew this wasn't going to work.' If you hear yourself saying those things, say 'Stop!' enough times that you stop seeing it that way. Look, it doesn't matter if it's true. You have to learn to control your little voice. So you attribute it to outside sources.
Secondly, when faced with adversity, say to yourself, 'This is an isolated incident, which has no effect on the rest of the week,' as opposed to, 'The rest of my day is ruined. The whole week is going to be like this.' You've got to turn around and isolate the incident. Do not allow it to become protracted beyond that moment. Even say to yourself, 'I've got a new call to make. This is a new page it's over and done with."
For more on dealing with adversity and 20 more life changing techniques please refer to Blair Singer's book, Little Voice Mastery.