Almost every professional photographer started out in some other field: Elliott Porter was a doctor, Ansel Adams was a pianist, Galen Rowell was a mechanic, Bob Krist was an actor. I am still a Business IT Advisor but you never know. If these people can start from nowhere and sell their work, so can you.
The nice part about selling photography is that anyone can do it -- you're not dependent upon physical ability, age, or background. It's more about art and energy. The photographic market is so open that every photographer and publisher I've met is pleased to give ideas and suggestions.