It's not easy but it is possible to let these kind of thoughts (like any other self-destructive or negative thoughts) come and go from your mind. Someone once told me it's kind of like if someone is knocking at your door and you just don't answer it. Just tell yourself, "Yes, I am having that thought again." And then let it go.
Just because we have these thoughts, doesn't mean they are a true reflection of us. They are thoughts. They are not us. And thoughts can run the spectrum between very, very negative and angry thought to neutal thoughts to very, very wonderful thought. None of these defines who we are. It's are actions that define who we are.
Good luck to you.