Take a look at the attached leaflet with suggestions and support for both parents and older children.
Here is a comprehensive link from Childline with an whole range of anxiety advice from panic attacks, to sleep, social anxiety and much more.
Also from Childline, Ask Sam. Children can write a letter to ‘ask Sam’ about worrying thoughts, feelings and experiences. Every letter gets read, but not everyone gets a response. Feedback on common problems are shared online.
Here is a simple NHS booklet to help adults understand anxiety in children, it could be used with older children as a self-help tool.
Here is an NHS ' Coping MenuCoping Menu'.
Here is a link for self-help for adults from the NHS.