[starpilot]

Unprofessionalism? Retracted offers aren't new. During the 2001 recession, many fresh graduates newly at Boeing had offers retracted. At my current company, one employee left to join Doctors Without Borders. We gave him a farewell dinner, and talked about the work he'd be doing abroad. Two weeks later he was back in the office. Turned out, DWB couldn't take him after all (I don't recall the details). He made the best decisions given the information he had. He did nothing wrong, and nor have you. Explain the situation to your employer. You have nothing to be ashamed about, but maybe your new employer does.

And stop tying your self-worth to your career. You are not your work.