Mandi,
Many have offered you sound advice here. I can't add anything to that. The reality is that right now there isn't much you can do for your husband. You can, however, do alot for your sons. I would encourage you to consider what would be best for them and what can you do for them. Alanon may or may not be the right answer but those involved may have a better sense of where you can go to look for it.
I have always been amazed at the strength a mom has when it comes to her children. The road ahead is a difficult one. I know that, because you walk it with and for your children, you will be able to. I have no answers for you. I can offer you my prayers; for your husband to find the healing he needs, for you to have the strength you need and to find the direction that would be best for you, for your boys that they will know the love you have for them and with that be able to grow into good men, and for all of you as a family to once again have the joy found in a healthy family.
Peace,
Fr. Mike