I think that breaking up is always difficult. Especially if you have been together for any length of time.
It is important to dig beyond self, and decide what is best for the both of you. This can be very hard concidering that we are human and that means we are also unique. One may think the relationship is wonderful, while the other can not go on.
I have personally never been one to impose myself (to a relationship) with someone who does feel it is working out. It always hurts, but you can also find comfort in knowing you did the right thing by respecting the feelings of someone you care deeply about.
That is true love...