how can i make my boyfriend more caring and know that he can lose me in any second if he didn't improve??

first of all we love each other about 3 years of passionate love caring so secure and every means of love any 1 could hope. over a month ago he started 2 be less caring less passionate and then he gets back and then he neglect me i forgave him bec. i love him and he loves me! as he never confece that he made a mistake he thinks that amalways the mistaken one plz help me and tell me what to do bec i can't live without him!!!