depressed

Finally got a job interview for a position I really like and has potential to move up in a decent company. But run into the same problem my friend had a few months ago. Due to confidentiality agreement with my current employer, I can't show anything I did in the past several years, which means, I can't show anything relevant to the job. this whoel issue depresses me and makes me feel bad about the upcoming interview. never had this problem before. always confident and comfortable with interview, but this time things are so different. can't show anything relevant, don't know what the audience would think... losing control.