Bridesmaids dress too small! Freaking out.

Hey guys! I'm not sure if this is the right forum to post this, but here we go. I am in a wedding on May 19th. I just received my bridesmaids dress in the mail and it DOESN'T FIT! It is too small around my chest. I ordered the dress according to the websites measurements months ago and now I'm kicking myself for not going up a size. I'm completely panicking! I do not have enough time to send it back and get another one. I'm going to try and lose what weight I can (if that will even help) and duct tape or corset myself in, but do any of you have any other suggestions? I don't really have the money to have it altered since the wedding is out of state and we're in the middle of moving, we're already stretching ourselves thin to attend/be in it. It's a strapless dress. I don't want to stress the bride out about it if I can do something to get into it. Any suggestions would be really appreciated! I'm sure I'm probably just boned, but it never hurts to ask.