trust issues

Alicia

I cheated on my boyfriend in the first month of us being together. I told him about it in that first month and i told him how sorry I am. we've been together for 9 months. i also told him about my past with underage drug taking, smoking and alcoholism. he can't seem to trust me because of all of that even though I have changed a lot and I am very selfless and loving and caring towards him. How do I get him to trust me again?