Hey hey hey
I have a theory and a method i discovered and created to eliminate negative self-talk by addressing it instead of resisting it by dismissing it or countering with a positive thought. For a more indepth look at it, you can go to my blog at uzumakinaruto.wordpress.com.
Anyway, my theory is that every thought from your other-than-conscious has a positive purpose, it could be to protect you from embarassment or failing, etcetra. So, what i suggest you try is to talk to your other-than-conscious. Recognize that its sending out a thought for your own good, and then explain why it doesn't serve you anymore, and tell it to please stop. Talk to your other-than-conscious as if its a friend, it is listening and all you need to do is to talk to it.
For example, i recently had images of a knife slashing through my organs popping in my head which was pretty disturbing to say the least, but i talked to my other-than-conscious by saying "hey i'm not sure why you are sending this image through, maybe its to protect me or something else for my own good but it doesn't serve me because all it's going to do is to attract this event to me. So, i hope you can stop feeding me these images". And instantly, the images stop. A knife may appear but the image automatically stops before it goes to the slashing motion without any conscious interference.
I've only discovered this method recently but its been a great success to me (:
