What should I do next in order to become employed?

So I just got back from an appointment with a temp agency. Skipping ahead to the end of the meeting. The only position for which I am at least partially qualified is as a secret shopper. I say partially because secret shoppers must be 21 to 25 years of age. I arrived seeking an administrative position. Despite being entirely capable of conducting administrative duties, I will be overlooked due to my complete lack of inexperience in that field. The temp agency’s representative assured me that she would keep my file on record and contact me if a position presented itself.
I have been seeking employment for two years now and am very discouraged. Because of my physical limitations and lack of experience, save for 6 moths in retail, I have come up empty.
What now?