Frustrated!

I don't even know where to start. I am just so frustrated with dealing with my ADHD husband. We've been married almost 30 . The biggest issue for us is his emotional dysregulation (anger) and  communication issues. I am constantly interrupted and stifled. I cannot express anything without being talked over, interrupted or argued with. We did the marriage sessions, which  is an 8 week course. He's always too busy with something.  It took us one year! And we don't practice any of the strategies Melissa taught. He has been promising to get treatment but has been unsuccessful. It is extremely difficult to find someone who specializes in ADHD who has immediate appointments and takes insurance, most do not. I can't believe how much money these people charge!  We bought the books, did the sessions and he had a hard time finding a therapist and finally found a doctor to prescribe medication.  He can't take most ADHD meds because of high blood pressure so he tried an SSRI. He had bad side effects so tried another. I asked him if he felt it was helping ( I noticed no difference). He said he stopped taking it! It had only been 3 weeks!  I told him it may take that long to see results so he started again. 
I'm  babbling. He works a crazy schedule and recently had to a take over his parents affairs because of their declining health. This has caused him tremendous stress because he's not good at it. I have always been the one to pay the bills and managed our household finances and now that he is responsible for theirs it's just another thing taking up his time and causing him stress. 
Everything comes before me. We go days without meaningful conversation, he falls asleep on the couch most nights and I'm ignored. When he's not ignoring me he's nasty, argumentative and defensive. I cannot talk to him about anything. I can't express my unhappiness or frustration because he will just interrupt and argue and get defensive. I will be shut down. I am just so sick of this. He is  generally apologetic and wants to make things right but nothing changes. I am losing my patience and I feel like I have no one to talk to. No one. People do not know about his ADHD. I don't want to tell anyone because it would violate his privacy. So what do I do?