OK, so gender expression is just appearance, presentation, personality. Fine.
Gender Identity I still don't understand.
You said:
GENDER IDENTITY
Our sense of identity in relation to gender, how we see ourselves as a gendered person, Man, Woman, Neither, Both.
This doesn't help me to understand what you mean, so I found this definition that you gave earlier:
I am using the term GENDER IDENTITY to mean a persons internal sense of gender.
In order to understand this definition we need a definition of 'gender'
Yours is:
I am using the term GENDER to mean Men, Male or Women, Female or Non-Binary Gender.
This definition is unsatisfactory, since men, male, women and female are sex categories, not gender categories. Non-binary gender is some sort of gender but is not defined at all.
I don't know what my gender identity is, or even if I have one. What should I do to work out what my gender identity is or whether I have one at all?