help!

I can't seem to quit my job. It's not like I'm quitting right now, just next semester. I am having a hard time with this. Everytime I try to tell my supervisor after work there are people around and or she is busy. I guess my question to you is... would it be horrible etiquette to send her an e-mail telling her I need to talk to her about next semester and that I won't be able to work and that I just need to meet with her sometime, or should I just tell her after work. What do you think?

Another reason that it is so hard is that I just plain feel bad, and I shouldn't, at all! It's not like it's my career or anything, it's just hard because as I've said I have NEVER quit anything before, ever. It's a scary thing for no reason. I just don't get it. I need to do it as soon as possible because it will make me feel better and give her plenty of notice. ... ugh.

Sorry my blogs have been so uninteresting lately. I apologize. I've had a lot on my mind and a lot to do!