Definitely a pickle but not an entirely uncommon one. A college professor is going to be too long ago, but a peer might be an option. Another one is to look to activities you're involved in (outside of work). Or perhaps a diagonal higher-up you can trust (mentor at your company)? Schools understand you might not want to let your employer know but it does put you at a disadvantage.

not entirely uncommon, as noted. Make sure you explain your situation in the optional essay provided by the schools. Clients might also be another avenue to explore. Steer clear of friends, family, and faculty (unless you have continued a relationship with a faculty after you graduated). cheers, alex