Yeah, you're handling it basically the exact way you've got to haha. I'm going into health care as well and just expect things like this to happen at more than one point in my life. A total fml moment, just gotta bite the bullet and go with it though.
No idea why the spot would be given to someone else, kind of odd. The total lack of informing you about the situation is odd, but usually for something like that there's a good reason behind it that they can't always disclose.