Try www.wpath.org. It is all licensed gender therapists and you just pick your State under "Find a Provider" and hit submit. If there is not someone close on the list, call the closest therapist and ask them for a referral to someone who is a gender therapist, but is not a member of WPATH, but is still qualified.
As an aside, although there are no doubt a lot of good therapists on Psychology Today, there are a number who have transsexual listed as a specialty, but it isn't. I have talked to a few who said they clicked gay/lesbian and transsexual was added by the site itself. Just make sure you ask (on the phone) before you set the appointment, if they have experiennce in this area.
