Hey, agent. Well, I don't know for sure what you could say to your mom to try to make her a little more accepting, if there even is something you could say.
This letter is pretty selfish, she's pretty much trying to guilt you into being straight. Maybe you could write her a letter too, since it is much easier to say what you want in an organized manner and you're not actually interacting with her when she reads it. It's easy to get too emotional in these situations, you could start arguing and you'll forget what you wanted to say in the first place, so I think a letter is a good idea.
Try to address everything she mentions in the letter, the most important part being how being gay is a choice. How could she know being gay was a choice? She's not gay. People can't choose who they are attracted to, and if they could, then why would they 'choose' to be attracted to the same sex if they knew it could make their family and friends turn their backs on them?
That part about not having the balls to tell her is stupid. How could you tell her if you knew this is how she would react? I wonder if she'd have the balls to tell you something that could potentially make you treat her like this. And the whole part about everyone crying when she told them, that's outrageous too. That's meant to make you feel guilty, as if you were doing something to them. This isn't about them, it's about you.
I guess you could try explaining to her what starting to realize you like boys is like, the fear one feels and how one tries so hard to change before we can finally accept it. But I don't know if that'd do any good, it sounds like she simply refuses to believe that it wasn't your choice. Like hanshansen said, she probably can't accept it cause it would make her world stop having sense.
Sorry, reading something like this pisses me off, I can't even imagine how you must be feeling. I think writing her a letter and trying to talk it all in a calm manner is a good way to try to get through to her. Try to make her understand that this isn't something you 'chose' to do to hurt her. Being gay is a part of who you are, you're still the same person and hopefully she'll be able to see that someday. I hope you get through this, good luck.
