It's sad when this happens but my advice to you is to say a very firm NO.
You could consider writing a letter telling of your disgust and feeling of betrayal by her, not once but twice. Tell her that you have decided that, because trust is important, your health is important and she has shown that she cannot be trusted, you no longer consider her a friend and don't want her to contact you again under any circumstances.
If you give in and agree to see her, she then has the upper hand and is very likely to manipulate you further, knowing that however badly she treats you, that you will go back for more.
If you want to be abused in this way then go ahead but I think you'd be the biggest fool to do so.
She's pulling the strings and you are the puppet.
Tell her to get lost and if she persists, then report her to the police as that is harassment.
Who knows, she might even be telling 'the bully' all about you and you willingness to be friends whatever the cost. Do you want to be laughed at?
Why not meet other people who deserve your friendship?
Remind her, in the letter, that you don't want her (or anyone else calling on her behalf) to come to your home or contact you in any way.
Be firm, be confident and don't give her the stick of friendship to beat you with.
Let us know how things turn out and remember that you can always rely on GN to support you in any way we can.
Take care 