Thank you to everyone for the replies. Keah, I also have Hashimoto's and arthritis, so I understand there is also a possibility that the Hashimoto's could cause more problems down the road. I looked more into the pilates certification today and, as bektold said, the full certification is pretty expensive. The mat certification is only a few hundred dollars, but I guess it depends on what my gym would require me to have in order to teach. I plan on talking to the aerobics director just to see what she says. It's not like pilates is my life-long dream, just a more recent interest that has come up. HR was always what I thought I wanted to do, but I've learned that I don't like having to deal with problems all day long. I have a bachelor's degree in business mgmt, so anything I'm looking at now would require a lot of school (since most of what I've looked at is health related...a totally different set of school requirements).
I think maybe some volunteer work would fill the void that I feel, but I haven't been able to find something I'm passionate about lately that is in need of help. I've done lots of volunteer work, but nothing that I would want to do for years on end. I wish our chapter of the CCFA didn't break up, as I was supposed to volunteer for them. Maybe I'll just call some places and see if they would allow a volunteer...even if they aren't actively seeking them out.
Thank you all for the suggestions. I admire those of you who were able to stick it out and finish your Ph.D.'s or law school...my arthritis is much worse than my gut and I still don't see how you had the energy to do it. =)