I have a feeling you won't like what I'm going to put, but you asked for views and I'm with noblegiraffe, to be honest. Your week probably is easier compared to his, given that he works long hours, seven days a week and has the responsibility of being the sole wage earner, plus the accountability of being self employed.
I've worked full time (as a teacher) and stayed at home, and staying at home was less stressful than working full time. Yes, children are tiring and you don't get much peace, but it is an entirely different kind of stress / pressure and, ultimately, it is enjoyable.
It's not a debate about how valuable being a SAHM is, it's about whether he feels that the burden of bringing home a wage is being shared. I don't believe being a SAHM is a 'job'. To me, employment means working in exchange for a wage. If you don't earn a wage, it is voluntary work. If it involves looking after family members, that is a life style choice, not an occupation. Lots of women have a 'job' and a family, so clearly there is a distinction.
It sounds to me like he wasn't expecting you to have 12 years off work and not return at least part time. You say it has 'worked out well' for you not to work as your husband works 7 days a week- does he see it like that? Or does he work 7 days because you work none?