Haven't been to find anything online.
Erika,
There is one at the Owen Brown Interfaith Center in Columbia, MD. Not sure what nights, but I could find out if you are interested.
Moni
Following this topic, as I'm in the Baltimore area as well...
I haven't gone to support groups yet, but when I go full-time over the summer, I'll probably try a couple out.
I believe on this page this is the Columbia meeting that Moni mentioned - contact info provided.
https://www.pflaghoco.org/programs-and-services
The other one I know of is the TransBaltimore meeting at the GLCCB in the Remington / Old Goucher - they appear to meet every other week:
http://www.glccb.org/programs/glccb-events-calendar/
That's all I know of near Baltimore for adults. In addition, there are meetings in Bethesda and Frederick.
Sarah
There is a gender convention in Harrisburg PA next month. The Keystone Convention at the Sheraton.
http://www.keystone-conference.org/ Should be several hundred people showing up, just like you. If you have never been you soon realize all the ideas you had that you are alone in this world are not true. Going to Gender Odyssey changed my life three years ago. This is a similar convention just on the east coast.