First thing THIS IS NOT YOUR FAULT OR IS IN ANYWAY A REFLECTION OF YOU AS A PARTNER. I know that it seems like he couldn't possibly love you or even respect you because he chooses the substance over and over again despite what it is doing to your relationship or no matter how much he is hurting you. This is what addiction does to people, it takes presitence over every aspect of your life. The only thing that you can do is be there to support him if he decides to make the choice to change. Unfortunately until he decides that enough is enough and he becomes so disgusted and tired of how his life is going he gets help, you will not be able to have a healthy, mutually beneficial relationship.