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.

Random Quote

In fact when you combine stem cell technology with the technology known as tissue engineering you can actually grow up entire organs so as you suggest that sometime in the future you get in an auto accident and lose your kidney we'd simply take a few skin cells and grow you up a new kidney. In fact this has already been done.