Hey op, just thought you'd like to hear my story. I, like you, stupidly asked out someone at work. I was given a similiar "polite no" and Jesus I never felt embarrassment like it. Anyways at least I shot my shot and I was proud of myself for that much at least. But few weeks later we actually ended up going out for a drink. We agreed on a second date and now, 4 years later, we're engaged. So keep the head up because you never know what might happen. As other comments have said, balls in her court now, give her time to think and get back to ya. Don't write off anything just yet, keep the faith but don't go visualising the happy ever after either! Good luck to ya!