Just because you can't perform a certain type of work doesn't mean you should abandon a career goal. Serving as an apprentice will fill the gaps of your knowledge. The best things in life usually involve a personal sacrifice. If that means working without pay, so be it. Critics will question your choice, saying it puts you in a bad position. Don't listen to their warnings. You've reached a crossroads. If you don't make plans for the future, you'll be stuck in the same place indefinitely.