Avoiding Confrontation with ADHD Spouse

I have spent the day reading posts on this site all day and cannot believe it has taken me this long to find you all. My husband is ADHD. We have been married for 15 years. He was diagnosed about 8 years ago and it has been his crutch ever since. He was a very successful construction project manager, then became a realtor. He was driven, focused, and hard-working. He supported me while I was in law school and continued to do so until I found a good firm to work with. Since his diagnosis, he says it is too difficult to work. I told him it's fine if he doesn't want to work, but he needs to maintain the house and take care of the boys. We have two boys, 12 and 10. He doesn't make it to any of their games on time, doesn't help with homework, and, during the summer when they're home, he stays in bed and watches movies while they run around the house with no structure. I work 10-12 hours a day, leave work to get them to practice or school activities. I have to leave the boys checklists and they call me at work if they need anything, even though my husband is in the house. The exterior of our house is in shambles, and I had to hire cleaners to care for the inside. He yells a lot, ignores us, and basically acts like he doesn't want a family. Any time I cry to my husband that I need a partner and I feel like I'm drowning, he tells me to F off. When I suggest that he time himself during the day so he can determine where his day is wasted, he tells me to F off. When I ask what he did during the day, he tells me to F off. When I ask him to try to make dinner, he tells me to F off.

And now here is my dilemma. When he does get involved, it's embarrassing. He is quick to get angry and think the worst of anyone. We are always late to events when we drive together. He often disappears and I'm left waiting for a ride or calling him repeatedly. My older son plays baseball. His last tournament did not go well and my husband is furious. Mind you, his season began in November and the entire season went really well, except this ONE tournament that my husband is hyper focused on. We have a 20 minute post-season conference with the coaches this week. My husband says he intends to tell the coaches they suck and that my son is done playing with them. My son loves this team and these coaches have been really good for him, with everything he is dealing with at home. My husband also doesn't let anyone speak and often speaks loudly over someone when they try to talk. I tried to tell my husband that our son should continue to play for this coach and this has been a great season overall. He told me these coaches are assholes and he intends to tell them so. He said they can't shut him up and he will speak for as long as it takes. 

Our son will be humiliated. I will want to crawl under a rock if my husband behaves as he says he will. What do I do??? What cn I say calmly to my husband to get him to back down and realize he's not thinking about our son?