You should tell yourself frequently 'I will only react to constructive suggestions.' This gives you positive ammunition against your own negative thoughts and those of others.
Each of us seems to have a main focus, a particular idea of practicality - a concept of 'what we want out of life' against which we judge our experiences.
The easiest time to cure an illness is before it is accepted as a part of the self-image.
To make sense to us as physical creatures, any 'truth' must undergo transformations, be couched in certain terms or we couldn't understand it.