key words and phrases which repeat themselves and are negative, look at what phrases and words you keep telling yourself, and when you see yourself repeating the negativities try changing the thought pattern, it can become like a groove in a record repeating itself at times, so take, for example , i am worthless and when you catch yourself thinking it, change it to the opposite, i am not worthless, doesnt seem to make much difference in the short term as you can think whats the point, but it does make a difference given time, reverse negative statements about self, or if that is too much then at first change them to less negative statements, ie, i am worthless to i am not as good as i could be, its a slow process of change reflected in self image and is an ingrained thought process that can be a pain to break out of , but persevere and it can make a real difference.