A high risk in which we tend to fall with these intrusive thoughts, is to use almost always the word "no". "I can not, this I will not be able to overcome, I will never be forgiven, I will not be able to get it ...". These kinds of thoughts are not constructive. They are fully and absolutely destructive. Also not only are they negative, but we come to believe them, hence a large part of their danger.
Far from giving us a solution and to relax, it makes us fall into an abyss with no way out. What if we do an inverse exercise? What if we build more creative thoughts that can give us some satisfaction? Creativity is important and in the same way that we use the "no" for a thought, we can use more real concepts. For example, instead of saying "I'm always wrong", we can replace it with "sometimes I'm wrong, but I also have my good times".
A mistake is an opportunity for improvement. A door that closes, are two that open around us, it is simply to know how to see them.
One thing we must keep in mind is that we have the mind of Christ, that is biblical, the battle is in our mind, God always has thoughts of good and not of evil, of health and not of disease, of wealth and not of poverty , of blessing and not of cursing.