Hello Art,
I'm also sorry to hear about your experience with your mom. I would like to suggest, though, that you check your assumptions before taking it too seriously. I don't mean to say that her statement didn't happen, nor that she is telling you her bias - those are very real. But, until you do actually tell her you cannot really know how she will react. Perhaps (at least we can hope) that once she realizes that it's her child who is experiencing such trauma then her opinions and reactions will change.
We could even imagine a scenario where she had noticed a transgender person in her soap opera and reacted positively, only to react negatively later when, here again, she realizes it's her child - not some TV actor.
I think it's all too easy for all of us (especially me) to jump to a negative conclusion based on assumptions that haven't been checked out. That said, she gave you some information that hurts to hear but maybe it will help you as you prepare to come out to her.
I wish you the best, Art. I really do.
Hugs,
Emma
P.S. Please don't interpret what I'm writing to be telling you "to get over it." I certainly know that you're hurting and that's what you need to do now. I just want to add my voice that you are heard, valued, and accepted. You will get through this.