Hi, I don't know if I can be of any help, but I will pray for you before I close my eyes tonight. Not my husband, but my mother is in a similar funk. She has been an addict for about twelve years give or take. She was in rehab after rehab and never could kick it. According to her she finally did, and after a five year hiatus she and I are just now rekindling some sort of a relatonship.
Long story short...she is still using. Not as frequently as she once was, I believe I have caught her before she spirals. I have been on here trying to find out sure signs...she meets most all. I hate this for you. I guess that the best thing to do is to always be one step ahead(sounds like you are) Set your bottom lines and demand the help that you need. Counselors, doctors, pastors, whomever just get it and stick with it. I now see that the worst thing that I did was to cut my mother out of my life. They need to know that we love them and hate their addictions (good book by-the-way). However, when the bottom lines are broken and your health and well being are jeopardized other actions are almost necessary. I think that as long as he is willing to help himself he deserves your support. Hang in there.