Ginny,
Wife's/moms always seem to get the short end of the stick. The kids have grown up in your home, they are aware dad was sick. Explaining to the kids that dad needs these therapy meetings to help him get well, I think the kids will understand a little better.
Once again, you thought him getting sober would lighten the load. But once again the addict, gets away without helping. This is where the resentment comes in and you need the help. He goes to 2 meetings a day for help and you barely have enough time with 5 kids to go to the bathroom. Ugh!! We get it, that is normal.
Reread what Eddie said above. He is 7 years sober and look at all he does. That is what the aa motto is, giving back what someone gave you. He is truly working his program everyday. This is a life long program, if not he will fail.
But you do need an hour or two a week for support of you. Just like honeypig said you can't give, if there is nothing left to give. Deep breaths, one day at a time, serenity prayer, these all help. It's not a race, but a marathon my friend, you can do this, if he can!!! Big bear hugs, you got this!!!!!