Oh, come on! Why does this keep happening? I just typed a 5-minute reply, clicked "Submit," and it said my message was too short. Sigh... the summary is:
Don't stay in a relationship if you're miserable. He will not change for you, and it is unfair of you to expect him to. Nobody likes changes, even if the status quo isn't that good. It's scary to go out on a limb, but trust me, you will be much happier in the longrun. You may be sad for a week, a month, maybe even a year if you guys were really close, but then you'll be happy for 50+ years.