Big Paws Only Dog Forums

 Ok so here is the deal. Recently we were given a 2 year old Female English Mastiff, named Molly. (Her previous owners couldn't properly care for her). She was abused by her previous owners. I have noticed she is especially on edge around Men. I myself am a young man and she seems almost overly possesive of me, I find this strange seeing as she doesnt like males. The problem begins when i leave the house she gets extremely ansy, barks and whines. How do i solve this problem? also does anyone know any good techniques to overcome her skitishness around males?
                          Any help would be great, thanks.