What sort of support systems does your husband have in place? Often sobriety is easy when the seas are gentle, but when they get rough a support system is necessary to prevent a relapse. Does he attend any peer support groups? Does he have a mentor/sponsor? What about a trusted medical professional? I suggest he reaches out to anyone he knows who has in the past offered emotional support and comfort in times of need.
If your partner has any hobbies or interests he may have a hard time engaging in them at the moment. Often periods of strong cravings and obsession about drugs can make other activities seem mundane. This is called anhedonia. Try to gently remind him he likes these things and that it can help relieve some of the uncomfortable feelings he has.
It's been my experience and the experience of others whom I know that when someone has a period of sobriety up (3 or more months let's say), their cravings for drugs doesn't come out of nowhere. Usually (but not always) there is a trigger which causes it. This trigger could be external or even internal. Has anything stressful or difficult happened in his life recently? Things like this are external triggers. Take some time to think if anything could be causing him to feel his obsession with drug use.
Internal triggers are more difficult to manage. When someone gets clean it is imperative they mend their lives which have been damaged by drug use and begin to move forward. This can look like many things to many people but for me it was enrolling in university and starting a family. Having other things that were fulfilling in my life made it to where when my cravings for Heroin returned I was able to more effectively manage them because I had other things in my life I valued.
Is your husband channeling his energy into creating a fulfilling sober life so that returning to Methamphetamine use doesn't seem so attractive?
Even years on from the depths of my drug addiction I still recall the experiences I had fondly. This is an illusion. Our brains are wired to seek dopamine with little regard for the pain it can cause oneself. Remind him of how much he was suffering when he was using Methamphetamine. It can be easy to forget the hurt and only think of the good effects the drugs cause.
In the meantime I'd suggest he attend a peer support group. Narcotics Anonymous (NA) is probably the easiest and most accessible for your husband, it isn't for everyone but in times of crisis a peer support group can give someone the strength to move forward. To find a NA meeting in your area visit
this website.
I'll include your husband in my prayer tonight. Good luck.