Hey.
I've never dealt with this situation, but I can help.
You say your friend won't talk to you.
Well, i want you to think to yourself, Is she really a good friend??
Should i continue to try and get her back??

I don't want to be rude or anything, but if she doesn't like you for being different, then i wouldn't waste my time trying to talk to her.
If she can't accept you for you, then i don't think she's a real true friend.

Now, about your mother. I know how it feels when people say that gays or bi's shouldn't be here, but the thing is, they don't know what they're saying. My parents know about me, and they don't care.
But they sent me to a psychiatrist. I found that offensive, but i just don't care.

I think you should tell your mum. Taking into consideration what your mum said, I think she'd still love you no matter what.

I hope i helped you in some way...
If not, I'm sorry...