Help! does he still love me?

my bf and i have been together for a year and 11 months on the ninth, but lately he doesnt give me the attention he used to and it feels like he doest care as much. he recently said he tries not to get too attatched to me because he leaves in july 2011 for the marines, so its not as hard. but it hurts because i LOVE him to death! i mean i want to marry this man. he used to talk about marrying me, but not anymore. :/ now he talks about leaving to the marines. what do i do? plz help