Hey Lizzie,
I think if you make the decision you will have to realize at first you will miss your boyfriend but you can’t regret your decision. I taught english in Korea and my initial plan was stay for one year and almost five years later I finally left. If this is something you want you should do it, you don’t resent your boyfriend foo holding you back, which you might unconsciously do in the future. You need to do it for yourself and fate has a way of working itself out, i promise!
Here is a blog post I wrote about teaching English in Korea that might help. Good luck!
http://www.globedriftertours.com/teaching-english-korea/