My heart goes out to you as well.  I work as male, still.  
My workplace is an even mix of males and females, and my closest friends there are female, but at the end of the day, and for a long weekend, I am myself.  I still pass as male (barely), and get ma'amed often (oops!) but my work time is 35 hrs out of a 168 hr week.
A suggestion?  Have you considered changing jobs?  You can if you want to, and put yourself in a more comfortable atmosphere.  Before you say construction, drop that hammer!  You can, if you want, do many other things.  I take it you managed to do hrt? So, if you can't go fulltime, you can at least at the end of the day, be yourself!
All the best!