Rainsong,
I'm feel the same way! I work from home and travel throughout the southeast to hospitals and dr offices, so none of my co workers really know anything. I do have two close friends at work that i consider real friends (you know work friends v. Real friends) who I've told. The good thing about work is that it's not strange to work on a team for years and never meet anyone in person. I was a bit concerned about if I should discuss with the nurses at some of my sites. They are really gonna be able to tell a difference considering they will only see me every 6 weeks (seems the longer you are away from people the more you notice changes).
My husband is throwing a birthday party for me this Saturday. I'm a bit of a social butterfly, but just this once I want him to cancel, but I haven't mentioned that to him. We have a lot of parties and just this once I don't want to have it because there will be people there that I probably won't see until my next birthday. I guess I just want to let the next couple weeks slide by, flying under the radar and emerge after the new year.
When I lost 75 lbs before, I used to be outside daily walking around the subdivision. My husband continues to do that, but I avoid it like the plaque. My neighbors are super close to my hubby and I'm more the hi and bye type. I've promised myself that I'm honda start the Cto5K as soon as my dr clears me. I really do want to know my neighbors and 3 of my 4 closest friends are all runners. They always want me to coming running with them. Ha. Now I can run only if provoked...like running the airports to catch flights, but don't expect me to be able to talk during and after for at least 45 minutes. LOL
I said all that to say telling or not telling is up to you. Only you know how much you want to put out there and based on passed experiences with your students, how much they can handle. I still haven't told my dad and really don't plan to. Once I tell him, it would be the same as announcing it on CNN. I'll just let him figure it out. My mom, brother, and sister know, but they wouldn't tell him either. We have a family joke - never tell my dad anything you don't want the entire world to know.
Good luck with everything and do keep me posted on how it all goes!