In Love Feeling Rejected

I am in a relationship that I have been in on and off for six years. We are young but can live without each other. We suppose to get married on November 10 of this year. Lately I have been feeling like he want an out but then I try to give it to him and he say thats not what he want. he dont call like he use to, he spends less time with me. DO he want a way out why wont he leave when he sees the hurt. I tell him how I feel and it change for awhile. I am hurting everyday cant stop crying. I need help what do I do???