Denial and blame from ADHD husband (new to this)

My husband and I have been married for 5 years. In the beginning he was thoughtful, fun, etc and I had me we been happier in my life. After we got married things started to change. He has become unreliable and downright all over the place. Sometimes I feel like I have to do everything. I'm a RN with a stressful job and I feel like I always pick up the slack. The only thing I can depend on is knowing that he won't get it done. I feel HORRIBLE for talking so bad about him but I'm suffering. I could finish what takes him a whole days worth in an hour I swear! We have two small kids and my son (3.5 years) has started getting bad reports in daycare. He is unable to sit still and is disruptive during nap time. It's only though getting a tentative diagnosis for my son that I figured out my husband has ADD also. I know, I know I'm not qualified to diagnose BUT my husband exhibits all of the symptoms and has been told by others he's just too scatter brained. The big problem is that he completely denies that he has a problem and insists that I'm just too uptight. I was never a nag before but I can't just let everything fall apart as he would! Anything I try to say that could be considered criticism is met with angry, yelling and mocking me. He frequently runs into trouble with jobs because bosses see him as being distracted and not following through.   I don't want to leave the marriage because we have 2 kids 3 and under. I feel trapped, hopeless, angry etc. just wanted to see if anyone else has been though this. How can I stay if everything is someone else's fault and he won't even admit that he had a problem. I feel invalidated and alone and unsupported :( . I want to feel secure and happy again.