Atomic Bride
Can you talk her into letting you find your own dress? Maybe you guys can shop for one together? That way you can pick what you feel comfortable in and find an affordable price.
I think you're freaking yourself out over absolutely nothing. As a bridesmaid all you're going to do is stand there during the ceremony. That's all. You can probably even change out of the dress if you want to once its over. I feel like if you were to tell your friend that you don't want to do this because you feel unconformtable in a dress, she's going to be crushed. If nothing else, sit her down and tell her how stressed out its making you, and maybe she'll understand and try to change some things.
No, I can't. Everyone HAS to wear the same dress. I asked about changing out of it, but she noped that too, claiming she's doing pictures sporadically instead of all at once. I tried to find ways to make this work already but no go.