Sleep issues and codependency/parent/child dynamic

Hi all! This is my first post here. I'm in the midst of reading THE COUPLES GUIDE TO THRIVING WITH ADHD and almost every page relates to my relationship. It's been a long road of difficulty for me and my husband - been together for 18 years, married for 11 with 2 kids. My husband was diagnosed with ADHD about 17 years ago and has been on meds since. He also has depression anxiety, substance abuse issues and more. 

sleep had always been a HUGE issues for him, intially an insomniac, then sleeping too much. It never used to bug me until we had kids really - then his sleep patterns became problematic as he wasn't living up to the normal expectations of"people with young  kids". He would often be up till 4am then sleep till 12 or later when he has obligations to attend to, other times be in bed at 9pm and still struggle to get up the next day. He's ranged (typical inconsistency) from thinking his sleep is an issue that needs addressing, to thinking this is just normal for him and it's "fine" despite how it effects anyone else. I've ranged from waking him up, fighting with him to wake up or go to bed, leaving him be and not waking him even if he had something he needed to be up for, helping him set alarms to go to bed, suggesting "ideas" of how to structure his sleep etc. 

In my journey to be less codependent and "mothering", I try not to get involved anymore. I don't bug him to go to bed and I try not to get angry when he only gets 2 hours sleep (then thinks it's ok to drive the kids to school.....) . I only wake him when I have to (eg. I'm going to work and he needs to take kids to school). 
the thing is - I don't really know where the line is in the "mothering" . For example - on the weekend - if I don't wake him, he's unlikely to get up. I feel resentful (getting up every morning with the kids early) and I get angry, which leads us to fight. He doesn't usually get woken by his alarms (if he sets them) or even the kids jumping on him and so if I don't wake him, I spend the day angry at him. But I'm "mothering" him by letting this whole dynamic happen.
What's worse - sometimes when I try wake him it takes a while for him to get up - and he resists often by saying annoying things like "what for" or let me sleep another hour (at 9am when I've been up since 6am and we all want to do things as a family). Again what's worse is that I KNOW that he IS SOMETIMES capable of getting up on his own (with an alarm) if it's important and he's motivated - like when he had a new job. So this just makes me more irritated. 
I used to ask him to write on the whiteboard in our room the night before if he WANTED to get woken up and at what time, that way it wouldn't be MY responsibility but I would just be aiding him (probably mothering I'm sure but maybe less so???) but of course he never did this. I guess the whole issue never really effected him enough to want to work on it - but for me it's huge. We've discussed it in therapy - a lot of times - but still nothing sticks or remains "remember or changed" for long. This is just one of many many issues that are chronic and utterly frustrating. I'm reaching the point of separation being a real option. 
so what am I supposed to do? I'm damned if I do and damned if I don't..... 


thanks for listening ;)