It's never easy, Maggie. And no decisions are needed right now. You have time to think. Whether or not he's an alcoholic may or may not be a deciding factor in your ponderings. People stay in or leave relationships for so many reasons.
You've brought it up a couple times. I'd hazard a guess that even if you had a job outside the home, there'd be issues with finances and hard days requiring unwinding on his part. Being a SAHM is work. It's a lot of work. And if you were working outside the house, there'd likely be other expenses to offset the income, daycare for younger kids would be a huge one.