Welcome Luna!
Sorry you had to find us this way, but you picked a wonderful place to come for support.
If I may be so blunt, and IMO, yes your husband is an addict.
My ex-boyfriend is the addict in my life. His DOC was cocaine. All though he has been clean for 6 months (supposably), he will always be an addict........he's just a recovering addict now.
There are "triggers" for an addict, but again.....reading that he blamed your mom and what she said triggered his behaviors is ludacris. No one can make him use, cause his behavior, or make him stay clean.
My ex didn't think he had a problem either and could quit any time he wanted to.......but sadly that's just not the case.......not until they are ready and committed to sobriety which usually involves a program of some sort.
The best thing you can do is what you've already started and that's to take care of yourself. Actions more than words will show you how serious he is towards recovery.
My thoughts and prayers are with you both.......and again, welcome to SR.
Hugs
Kris