Hard to decide what to do with kids involved

I've been doing a lot of reading on here, and sometimes I see similarities with my marriage, but in a lot of ways, my ADD husband seems "not so bad" compared to some.  So then I wonder if I'm making big deals out of nothing, or if I'm the one that is the problem.

We've been married 17 years, and have come close to divorce twice.  The first time was after a pregnancy loss, husband was undiagnosed, I needed support and he played video games all day.  We got him medicated and both of us into therapy.

The second time was about 3 years ago - he was off meds, we were fighting constantly, and he ended up in a relationship with someone else that was not physical, but way too emotional.  He got back on meds, we went into counseling again, and struggled through.

But now, we are back into patterns.  He freaking refuses to take his meds on the weekends.  If he forgets during the week, he will come home at lunch and take them b/c  he knows he needs it to function at work.  But on the weekends, even if I remind him once nicely, or hound him, he will not take it.  I know he hates to take meds in general, even for a headache.  But I feel like we are just not important enough to him to swallow a couple of dang pills.  And he is a jackass off his meds.  I don't know if it's the impulsiveness or what, but he's very sarcastic, CONSTANTLY messing with the kids, and that's when he manages to stay awake.  He has managed to find a new doctor on his own, which I admit was a major pain b/c of the lack of providers around here, but he did it and has kept his appointments.  He gives me the Rx to drop off, which is fine, but I've asked him to call in the refills on his non-stimulants so that I don't have to make several trips to the pharmacy, and he can't even do that!!

We cannot communicate at all anymore - it always becomes a war of words and semantics.  It's up to me to find a time to talk to him when he's not distracted - so I turn off the TV, wait until the kids are in bed, etc., but I cannot pry the darn cell phone out of his hand, so he's still only half listening.  And then when it gets screwed up, it was a "miscommunication" to him - he takes no responsibility.

I'm trying to accept that there are some things he just cannot do, even with meds - executive function and all that.  But I'm also tired.  I want a partner, not another child.  I need to be able to rely on him for more than just killing bugs and cleaning up doggy doo.  I want someone who is present enough to see when I'm struggling and not wait for me to explode and then tell me he won't do anything until I "stop yelling at him".

It's hard to condense all of our issues into one post.  I just don't know how much is ADHD and how much is that my husband is just a jerk, and I didn't see it when we were younger.  Or did my screeching and nagging turn him into a jerk?

If we didn't have kids, I would be done, no question.  But we have 3 that are pre-teens, and 2 of them are also ADHD.  I don't worry for their safety with him - he's generally a good dad, but I foresee their weekends with him when no one would be medicated, and it would just be torture for them all.

I'm just not sure what to do.