How do I break it off?

Breaking up is never something that's easy to do. Very few people walk away from a relationship being friends.All you can do is lay your cards on the table honestly. Pray for the best but be ready for the worst.If he really cares the way he says he does then he should understand.But you can live your life worried about how someone else feels about what you want.No matter what the cirstances of what your relationship has become you must be honest with what you need and feel.Otherwise you are settling and that will only make you miserable.Then you will end the relationship because you will resent him for standing in your way.Keep things in proper prospective the relationship was what it was. It served it's purpose and now you are ready for what you feel you need.