It's hard to fathom how an addiction can tear apart a family, yet, sadly, happens all too often. I'm close to a few families, that this has happened. Self, included, like your case, no-one is going to say 'that' of my ex(says him), but reality is reality.

The important thing, is that you remain strong for yourself and your kids.
Are you the full time caregiver, at this point? Will the trip to the ER sway a custody agreement?
Reaching out, to all available supportive resources, is important.