This is a demoralizing (士气受挫) position to be in, but it's usually not the work itself that makes you feel as if you're not making a contribution. One of the world's most admired companies specializes in cleaning services, and its employees, who scrub office floors and bathrooms, believe they have reason to be proud of themselves and the work they do.
You need to discover a sense of purpose (使命感). Your job is making copies? Find out who needs them and why. Or maybe you need to shift your focus to what makes you happy outside of work—traveling, playing tennis, volunteering. Then you can think of your job as the means to make those activities possible. If you still think that everything you do is meaningless, then you need to prepare for a job change—because once you believe you're wasting your time, it won't be too long before your employer believes it, too.