Some more resources I discovered via a letter from CAMHS. I have corrected the hyperlinks so I hope they work but all of these organisations have useful information for young people, parents, carers and professionals on their website so please explore.
Huge Bag of Worries by Virginia Ironside.
The Relax Kids books by Marneta Viegas.
Overcoming Your Child’s Fears and Worries by Cathy Creswell.
Apps such as Calm Harm, Head Space.
NHS self help guide: https://www.ntw.nhs.uk/pic/leaflets/Self%20Harm%20A4 %202016%20FI NAL.pdf
Rethink Mental Illness: https://www.rethink.org/diagnosis-treatment
Coping with Self-Harm: A Guide for Parents and Carers (Booklet, Charlie Waller Memorial Trust): https://docs.wixstatic.com/ugd/cb4de2_5a21680b4112403188e50a6972309449.pdf
The National Self-Harm Network Forum: http://www.nshn.co.uk/
No Harm Done guide for young people: https://docs.wixstatic.com/ugd/b5791d_76fce29c6713470e9cee4b8c332f98dd.pdf
No Harm Done guide for parents: https://docs.wixstatic.com/ugd/b5791d_336e08e57fdf4d838783ed67c04df5f1.pdf
Recognising and responding to self-harm for professionals: https://docs.wixstatic.com/ugd/b5791d_336e08e57fdf4d838783ed67c04df5f1.pdf