I have yet to find one. The closet to any form of community support I have seen and received is from UT- Pan American. UT Brownsville should have one too, but if they don't they will likely have one soon as they get incorporated into the new UT-RGV system.
Your second best bet is to talk to the Stonewall Democrats of South Texas (sorry but most support here is partisan). They meet often in the Weslaco area and their leadership can help direct you to support outside of the world of academia. The only problem here is that even in the LGBT community, the T is almost invisible. Even at pride events by the community, the trans pride flag is rarely recognized.
Planned Parenthood used to offer some assistance, but that was before the new laws killed the Women's Health Clinics being run here. Now the closest center is in San Antonio to my knowledge.
Welcome to Texas, and welcome to the Valley!