My best friend has amnesia. please help.?

I'm really sorry to hear this. I can't imagine how it must feel like to not be able to share the memories and bond between you and her like you once did. I'm really not sure what to say, but if you really were good friends then I believe she'll take the same liking to you then she did when she first met you. You should put together a photo album full of the memories that were lost and maybe write notes about things you did together and the thoughts you shared as well as her boyfriend who I believe must be in real pain. I don't know if things will go back to the way they were but don't give up, if she's really a friend you cherish dearly hold on tight to the memories you shared and don't let them dissapear they're still alive as long as you hold them in your heart. Try and retrace through the past and try everything you can to try and strike a memory, keep repeating phrases, talk about big events. Don't give up, you don't want to lose a best friend over a silly thing like this, your friendship can overcome this, don't give up.