I have a crisis can somebody help me out?

Ok, so a month ago, my school Drama CLub had a meeting for auditions for Jekyll & Hyde. We all have to prepare a song. Even before that I told my friend, I am going to do Somewhere Over the Rainbow because I did it at a Talent Show and like one out of 300 people who came up to me said I wasn't the best person to ever sing that. Including Judy Garland, Katherine McPhee, etc. She said you should because she knew I sang it well I'd definitely get a role. Honestly, it's the only song, other than the Jekyll & Hyde songs that I can sing very well. Almost all other songs are a bust. Thing is, we cannot sing the same song as somebody else and cannot sing a song from Jekyll & Hyde so only song left for me to do is Somewhere Over The Rainbow. I SWEAR IT IS TRUE! I have told people before and from the songs I can learn in two days, (Auditions are tuesday!) it's the only one that sounds good at all. My friend wants to do it now. She knew I wanted to do it for MONTHS! Today she says she is definitely going to do it. I have know idea what to do. She is a close friend so I don't want to lose her but I will look like a fool if I try to memorize another song in two days. I have tried learning songs in three days and it was terrible. It takes me a few weeks to learn a song that's even a minute long. What should I do? I don't want to lose her but I don't want to not get a role and embarr myself. I am a 14 year old in high school with enough self-esteem issues. I really cannot handle more embarrment!