I forgot to tell that I think it´s not good to overwhelm an anxious thought, the better is to let go and wait for it to pass, because we know sooner or later it will pass. One example meditation give to me is that how our thoughts work: if we try to push down a ball in water, when we leave the ball, it will rise up much stronger.
Other similar example I recently read how our brains work (including who don´t have this problem we have): if I tell you " don´t think in clouds". What you are think right away? "In clouds". Our brain don´t read the word "don´t", it will skip to "think in clouds". That´s why it´s useless when we have panic attacks say to ourselves "don´t be nervous" , or like yours "stop the thought" don´t work. And when you tell "you are better than this" you are being depreciative with your self.