If you’re looking for resources around Gender, Sexual, and Relationship Diversity (GSRD) and Mental Health, you might find the following documents that I was involved in writing or editing helpful.
This free British Association for Counselling and Psychotherapy resource on GSRD is a comprehensive ideas for counsellors, therapists, and other practitioners including all the basic information you need to know about GSRD.
These documents were produced as part of my work with the LGB&T partnership. They contain guidelines for practitioners, and for LGBT+ people seeking support.
Also useful are these British Psychological Society guidelines for practitioners working across gender and sexual diversity that we wrote a few years back:
Dominic Davies and I wrote a couple of articles for The Psychotherapist on these issues:
And if you want a lot more detail, check out these two books that Christina Richards and I wrote together: