The bigger question that "will she accept me" is do you accept yourself for who you are? In the end you have to live with yourself and if you can accept and are happy with who you are then the rest don't matter so much. I know approval from parents is extremely important to a lot of people but they're not you and no matter what they can't see life from your point of view.
Be who you are and be happy and proud of that. (:
I know I will always be proud of people who stand against the odds and say out loud "This is me and I am proud of it."
Tell her to accept who you are.
You must be straight-forward about these things and if she doesn't like your sexuality, it will not be your problem. As long as you accept who you are, there will never be any impacts.
My mother had a very bad reaction to my sexuality too, but in time she seems to have accepted it. Like the others have said, if YOU'RE happy with who you are and are being true to yourself, then that's the most important thing.
I'm not denying that when someone so close to you won't accept you, that it hurts. I'm so sorry she's not being more open-minded and decent about it. Do you have any idea why she has such strong negative views? Do you think it might be a generational thing, or a religious thing? Perhaps you could talk about it with her - not even about *your* sexuality specifically, but perhaps about non-heterosexual orientations in general and find out what her problems are. A lot of hatred is driven by fear and perhaps if you discover she has particular fears, for example: perhaps that you might settle down with someone of the same sex and not have children as she has always imagined you will. Or that she believes that society as a whole is still unaccepting and she feels you and then by proxy, her, will be judged negatively. Given the use of the term unnatural, maybe there are religious roots to her prejudice?
She might not be willing to have a reasoned discussion with you, and that's OK too. If she constantly gets upset/hostile/abusive then you may find it easier just to put some boundaries in place and refuse to discuss it with her - your sexual life is your own private business and not a place for her to judge. It sucks that she can't just be happy for you, but it would be a shame for her negativity to get in the way with you having a perfectly natural, happy and healthy relationship regardless of their gender/sexual identity.
If you are under the age of 18/still live with your mum, and she really is that againts it, I would suggest not forcing the issue. I know it sucks, but, your safety is the most important thing right now. And being made homeless isn't safe. basically, don't come out unless it is safe to do so.
if you are independant/not living with your mum, I suggest trying to educate her about sexuality, but gentley, instead of throwing her in at the deep end. it might help wear away at her ill conceived prejudice.
At the end of the day, if she can't accept you for who you are, it is her loss. It's hard but we have to remember our parents are not saints, they are just human, and therefore not immune to human flaws. And if she really can't rise above her oppinions for someone she loves, then, she doesnt deserve you.
Good luck.
"I would be almighty in my own world of art, even if I had to paint my pictures with my wet tongue on the dusty floor of my cell." -Picasso
"No, painting is not done to decorate apartments. It is an instrument of war." - Picasso
'I have scars becuase I have a past; but they, like my past, do not define my future'