this is a very nice read. thank you for writing this.
being a mother myself, i know that it is CERTAINLY easier to accept that my child is EITHER a boy or a girl, emotionally and psychologically...but speaking as a mother, i would never think ILL or be DISAPPOINTED if any child of mine would be 'somewhere in between', in your case, gay.
but while you 'feel' that your mother is sad or disappointed, you should never assume what she feels...instead, you should move forward and since you have embraced and you are quite happy w/ your 'personality' and 'being' now...try to find ways to be a good person ...someone YOU would be happy and proud to be, and someone your mother would be proud of as well.