Burnout

Would you be working more or less hours if promoted than with all the fill-ins you're doing now? I would think you'd have more latitude on which extra shifts to take if you become supervisor.

I think you have to learn how to say no. Talk to your boss and let he or she know that it is causing too much stress.

I would definitely recommend speaking with your supervisor about it. Honesty is the best policy, afterall. I had a similar issue happen recently, and I did quit my job, but that was because I knew that I really could not deal with the added stress that came from the job. I sat down with my supervisor, and she was so understanding. If you let them know that you feel burntout, and that it would be easier if you had someone else to share these responisibilities with, maybe they'll work with you.

As far as the promotion, if you do think about it and find that it would be too much added stress, also be honest about that with your employer. Unless they're real jerks, I doubt that it would negatively affect you. In fact, I think it shows your responsibility and willingness to make the right decisions. Not only for you, but for the company you work for.

Good luck with everything and much love and peace!
Arizona