Cancelling will be the worst thing you can do. You're in college, which means that getting a job is the end goal. How else do you expect to get a job? My advice is don't be afraid to stutter. Start the interview by telling them that you have a stutter and quickly move on with the interview. This way they will understand why you may be blocking/repeating/etc, and for you the monkey will be off your back regarding not having to hide it.