From my kindle version of this book:
Let your thoughts play their tricks as they will. Concentrating hard on trying to forget oneself is merely another way of concentrating anxiously on oneself. Do not try to forget yourself. Do not try to force your way back into anything. Accept yourself as you are now, with all your strange thoughts. It does not matter what you think about, or how much you dwell on yourself, providing you do not do it anxiously. That is the key. It is the anxiety that tenses, sensitizes, not the thoughts. Accept your thoughts, whatever they are, as part of your ordinary thinking. Do not make the mistake of believing that there are certain thoughts you must not think, dare not think, as if there are parts of your brain you must not use. Use them all, even those that may hold an obsession; but use them willingly, shrink from none of them. None of us ever completely forgets himself. You are only much more conscious of yourself than you normally would be. This is not important, although it can be devastatingly frustrating. Accept your habit of introspection with as little frustration as possible. You may be often disappointed in the beginning. Be prepared for this. Thoughts may be fantastic when you are anxious. You may go chasing them to see how odd they can become, and the stranger, more unreal they seem, the more you may push on, as if compelled to find out the worst, compelled to challenge the worst. And do not make the mistake of thinking that this is mental. You are merely once more afraid of fear, but this time in one of its most bewildering and upsetting guises.
Weekes, Claire. Hope and Help for Your Nerves (pp. 131-132). Penguin Publishing Group. Kindle Edition.