I don't have a lot to say in this reply, but I strongly urge you to go to (RUN!) some Alanon meetings. These meetings are designed for people who have relationships with loved ones with alcohol (drug) issues. Alanon will teach you how to love yourself and respect the relationship with honesty and compassion.
It is unfortunate that your husband is doing what he is doing (or not), but ultimately it is his choice. You can't control his behavior, nor can you cure him. He has to take those steps of his own accord.
The best thing you can do for him is to be the best human being you can possibly be. Alanon will show you the way.
It's a heroes journey, and you are the hero.
Loving Kindness Meditation will dramatically improve your spirits; give it a try for just 3 days: http://www.youtube.com/watch?v=sz7cpV7ERsM