breaking up

I think it's time my boyfriend and I break up... the problem is I love him so much, and he is like my best friend, however I'm not nearly a priority to him in his life, he hasn't made time for me at all in the past month and a half.. I can't imagine my life without him... this is going to be hard but he's been making me upset and Is never with me. How do I encourage my self to let him go, even if my heart won't allow me to.