Higher education is exploding in this region, and engineering programs are featured at many universities. I used to be at the new public university in Cancún, La Universidad del Caribe (http://www.unicaribe.edu.mx/
), and they have an industrial engineering program, for example.
Without trying to sound too pejorative, I would say that many of the teachers in these institutions are people with less in the way of qualifications than you would find in people in equivalent positions in U.S. universities. Turn that around and that means that you may be relatively very well qualified, at least from the professional standpoint (don't know about teaching experience). Assuming that you have some ability in Spanish (although many schools also want people to teach in English, at least in some subjects), you may want to investigate this kind of career step. Even if not full-time, it could provide part-time, ongoing work that was rewarding both psychologically and financially.
Steve Rybeg, Manager (but a teacher at heart!)
Hotel Playa Maya