Hi Nowell,
I am pretty new to this site but certainly not new to the issues you speak of. Although I am not an addict myself, I have (and do) deal with the same issues. My RAH had been drinking and smoking pot for 25 years before just 30 days ago going into recovery. At several points in time he had tried to modify his drinking, stop the pot smoking, only smoke or drink on weekends and a variety of other useless scenarios. He had always been told that marijuana is 'natural' and non-addictive. He (and I) found out the hard way that this simply is not true. He tried to quit numerous times and always went back stating that it helped him with his anxiety. What I have learned by educating myself through books and speaking sith substance abuse counselors is that pot actually makes anxiety worse over time. It may initially produce a calm but it puts your emotions on a roller coaster ride! Add alcohol to this and nothing but trouble. He always felt depressed as well and was prescribed every antidepressant in the book. They had minimal effect on him and I now see why. We have both since learned that, not only is drinking while using antidepressants not recommended, it lessens the effectiveness of them altogether. At a certain point he told me he was just sick of taking the pills, them not working, drinking and smoking pot and still feeling like crap. He had to do this on his own though...no matter how much and how long I could see it, he didn't want to hear it.
In regards to relationships in early recovery, you should read the article entitled 'Relationships and recovery' that is on the home page at the top. I believe it is marked "Articles". It basically speaks about new relationships as sometimes being a replacement 'high' for the addict in recovery. I would say that after the high wears off then it isn't as exciting for them any more. I don't think the addict even realizes that he is functioning this way but it certainly makes perfect sense if you think about it.
When I read that he told you 'he is afraid he will cheat' it hit home to me because I have been told something similiar before and found out later that he had already cheated when he said this.....
I don't think you mentioned how long he's been sober or if he's totally sober (if he's smoking still, he's not sober) but my RAH was told by his Dr. that it wouldn't be wise for him to try to diagnose him with a possible mental illness until he has stabalized for a while.
In the meanwhile, take care of you.....