Trans Pride Brighton has been running since 2013 and provides a great day where trans people, friends, allies and family can meet and have an amazing time in a fun and safe space.
A sexual health service for anyone who identifies as trans, non-binary or gender variant (partners are welcome too). The clinic runs every month. All of their services are free and completely confidential, and their staff have been trained in trans awareness.
Formerly FTMB, Navigate is a group for transgender men, trans masculine people, gender queer people, non-binary people, those assigned intersex and/or female at birth that fit somewhere else on or off the spectrum, or those who are questioning their gender identity.
More useful links
MindOut is a mental health service run by and for lesbians, gay, bisexual, trans, and queer people. They offer a great number of confidential services run by LGBT workers.