Families Together London
Offers parent to parent style support groups that can be of benefit not only when you struggle with your child's newly disclosed or suspected identity, but also in upbringing tips and advice.
Families and Friends of Lesbians and Gays
Great advice line and support for parents of lesbian and gay children.
Charity offering domestic abuse and hate crime helpline.
London LGBT Switchboard
Great voluntary helpline that can help offering non-judgmental support and advice.