I *am* a parent... and my three daughters (two grown-up, one 11) will probably always call me "dad", despite my ongoing transition. So, I suspect that I may be a good example of a best-case scenario for acceptance of gender issues in my own children.
Would I still love them? Of course.
Would I miss their presentation of their old gender? It's hard to say, but I don't think so. The "secret" I've held for so many years, even from myself, makes it much easier for me to understand than it would be for CIS parents, I think.
And I think that is kind of the point. It would be easy for me because I've had over 30 years of knowing, deep down, that the body does not make the person, and that a person *can* be deeply unhappy with their gender presentation. I *know* how miserable it can be, and I would never want my kids to go through that for any longer than they needed to in order to be certain they wanted to change it.
Parents love and accept in different ways. I recently watched "Becoming Chaz Bono", and it was heartbreaking and, eventually, heartwarming to see Chaz's mom, Cher, go through her own acceptance process. You can tell, in the early interviews, she just wasn't dealing with it, because she knew and loved her daughter and couldn't imagine that her "Chastity" could ever be happy as a male, that it must be some kind of phase, that "she" would regret it eventually.
Over time, I trust (and hope) that your mom will begin to see that you are truly happy being a man, and she will be happy for you, too. She hasn't had your experience; she doesn't know where you're coming from, and she will naturally worry for you. It'll take some getting used to, is all.