Husband undiagnosed, 14 yr old daughter w/ adhd HELP!

My husband and I have been together since 2003.  We have had a really tough road to hoe, but I am so thankful I stuck it out and gave him unconditional love.  I have two daughters from a previous marriage and he loves them as his own but it has been extremely hard to cope with the relationship issues.  I knew in the beginning that he had anger issues and was "flighty" and had a, shall we call it, honesty problem.  He is also very impulsive and has put us in financial difficulty over and above the norm because of this.  Writing this makes me wonder how we are still together.  I fell head over heals with the "real" him and saw so much potential there for us that I had to give it my patience and love.  So far he has become the "perfect" husband.  Loving, romantic, always thinks of me, needs my input, asks my opinion and listens to it, respects and adores who I am, thinks I'm about the smartest person he has ever known, still thinks I'm sexy and beautiful even after another child and 30 lbs.  I could go on and on.  He also is an awesome step-father and friend to my teen daughters who only see there dad once or twice a year.  However, the flip side comes out and is threatening to destroy our relationship as well as my daughter who was recently diagnosed with ADHD.  They have the same symptoms and react the same way and butt heads all the time.  It seem that he sabotages her just to prove he's the dad or something.  To that end, we fight alot mostly about Nicole.  He tells me what a good mom I am but when we are fighting says horrible things about my ability to be a mom and that I dont do anything because I stay home with our 3 yr old and that I'm a bad housekeeper(who wouldn't be with 4 kids, two dogs, two cats and a husband that wont do housework just bark out orders).  He blames me for the fights saying I turn everything around to blame him and wont accept any responsiblity, he is sorry afterwards but conveniently forgets this on the next occasion.  He has a problem with cussing and saying inappropriate things in front of the kids and especially while driving and only gets worse when asked to stop.  When asked to stop something he just reiterates the whole problem again and again like a play by play and keeps on telling me his side over and over like I didn't hear him the first time instead of just dropping it.  Even when he is begged to stop in front of the kids he just keeps on and on and it hurts the girls and makes the baby very insecure.  When he is angry and especially when dealing with Nicole he cannot see that we have to be rational and talk calmly but only says needling things to upset the other person and blames them for the whole situation when it mostly starts because he overreacted to begin with.  At these times we cant have a normal conversation because all he seems to want to do is be mean and accusing of us, interrupt, deny that he has any blame and assume the worst of the other person.  He accuses me of undermining him when I think he is too harsh or overreacting and just gives up but then says I dont want him involved with the girls at all.  He gets so very petty when he is angry and does silly childish things that he knows will upset me, like deleting my  tv shows on the dvr or taking my company magnet off the car because he doesnt want me near him or something, or breaking something he knows is important to me or the big one.....saying something offensive or harsh to my girls just to get at me.  He has severe double standards and thinks the kids should just obey blindly nevermind how he acts.  I tell him Monkey see Monkey do but he says "my dad would have....."  so its black and white and nothing else.  We all live on eggshells with him so as not to "trigger" any episodes but my poor Nicole has similar problems so she reacts disrespectfully at times and doesnt realize it until its too late.  He demands respect but doesn't give it, especially when he is mad, and if she steps over the line he goes beserk and I'm stuck in the middle.  I know exactly how she feels as I was abused by my step father.  She feel like he thinks she is bad and evil, she feels like nothing she does is right, that she is trapped, that she isn't worth anything or that she is so very very alone.  I am trying desperately to counter this but I need help with him.  How do I reconcile both sides of him and keep my daughter's spirit alive and well.  I can't let her be hurt as I was.  It nearly ruined my life.  She comes first but we all have such a good family most of the time.  How do I get him to see he needs help and that he is wrong in his dealings with Nicole?