Shil,
I am an alcoholic in recovery, and I have not read your backstory so my comments are based solely on your original post.
I think text is great to stay in touch with the distance needed for your sanity under the circumstances. But text (and to a lesser extent email) can really easily be misread because it is impossible to be certain of the tone, ie sarcasm vs. empathy. "looking forward to getting you back, please don't take too long about it!" could have landed as criticism and impatience with his relapse. I know you didn't mean it that way, because I have the benefit of the other 95% of your post. He did not. Be careful of texting things that could be unintentional double entendres; keep it simple. Open ended questions about him and how he is doing are probably least "misunderstandable" ie "How is your day going?"
I would like to comment on the work situation. I was unemployed for 18 months after I got out of rehab. I too took the only job offer that I had, which was stressful, long hours, and paid far less than it should have. The only saving grace was that it was 5 minutes from my meeting place, and only rarely did I miss a meeting because of work. If I had to, I would finish my work at home after the meeting.
Your husband may not have had a position where this was possible. I can only say that working 72 hours/6 days a week and missing meetings would have been untenable for me. I would like to think I would have quit before I relapsed, but then again I know what my self image was like after being unemployed for close to 2 years. I might have tried to stick it out... at the risk of my sobriety.
I had been told that anything I place as a higher priority than my sobriety is likely going to cost both it and my sobriety. I now understand that this doesn't mean that I cannot have a challenging career, but it absolutely means that I need balance. It does not sound like your husband had balance, and it cost you both dearly.
These are the sort of things that make being in AA and having a sponsor so critical. I didn't get sober to spend the rest of my days hiding in church basements, whining about my life and drinking bad coffee. But I can never forget that I am an alcoholic, and my disease can make me think that I am not sick. I need feedback from someone who understands, someone who I know has my back. I sincerely hope your husband has a sponsor, because if he is anything like me, some days its awfully hard to know where the line is for balance in my life. Truth is, that's not just an alcoholic thing, we all could use some outside perspective every now and again.
So, what can you text to stay in touch but stay on your side of the street? "Hope you have a great day, I love you." or "How was your day? Thinking of you."
Hope this helps.