Commitment Issues?

Jennifer
My boyfriend and I have been dating for 5 and a half years now, and I'm ready to settle down and maybe start a family in the next couple of years. Only problem is he still hasn't popped the question. I don't want to hound on him and I've been dropping hints. I even came out and said for Valentines Day I want to become his wife..... We've talked before about marriage, but he has a lot of divorce in his family and he doesn't want to end up that way, but we've already said we want to spend the rest of our lives with each other. Also, he told me if i wanted his last name to just go change it. Why is it hard for him to propose? Any advice?