Hyper-focus or mania?

I'm exhausted and at the end of my rope and I guess I just need some support. My husband has not been diagnosed with ADHD, but he shows a lot of the symptoms, along with anxiety and depression. I've asked him to see a doctor about it but he hasn't been willing to go.

We just had a major blow-up and at times like these I fantasize about ending the marriage, although I know he needs me and I feel like I'd be throwing him to the wolves if I left. This latest conflict is that his parents are coming to visit tomorrow, and he's hyper-focusing on getting the house ready for their arrival. This includes wrapping up household projects that he started at least 6 months ago but never finished, despite my repeated requests, and fixing things that he "broke" (like replacing all the smoke detectors that he took down a year ago and then somehow lost). He's like a cyclone of anxious energy and is mad at me that I'm not helping him enough. He says that it always happens this way when people come to visit (me not helping), not realizing that he's doing it to himself. Normally, I feel like I'm the one who does the lion's share of the housework, not to mention managing our money and being the breadwinner and basically holding everything together. On the weekends I'll go around and clean the house while he sits on the couch. He doesn't make things like that a priority in the same way I do, and I've asked him to help me more but he only wants to do it on his own schedule. So I feel like I end up doing everything (or if he does it, it's after having been put off for what I consider to be an unacceptable amount of time) and I silently resent him for it. Now he's got this enormous list of things that he thinks he -- or, I should say, we --  need to get done for this deadline, and he's blaming me for not taking time off work to help him. It seems like a pretty unrealistic expectation to me, but he acts like he feels seriously victimized by my lack of urgency. All I can do is stand there and think, "Really? This is how you treat me after everything I put up with from you?" These things include drug and alcohol dependency, two DUI's, getting sued for an unpaid credit card balance, and anger management problems. It's like he just can't see the big picture. 

I just got a call from him in the middle of typing this (I'm at work). He's asking me again to take time off and come home to help him. He says he feels manic and like he wants to "put his head through a wall." He's feeling "paranoid" because a technician from the internet company is supposed to stop by and check our DSL lines, and he's afraid he'll miss him or not be able to answer his questions when he gets there. He says he's feeling so much pressure that he just wants to shut down. Now I'm starting to wonder if there's more going on here than just hyper-focus. His reactions seem pretty extreme. I want to help him but I feel like it's just a vicious cycle that will happen again no matter what I do. He admits he has a problem and I think he needs mental health treatment, but I don't know what to do to get him to actually follow through on seeking it. I feel pretty helpless.