How does your spouse's ADHD impact your children?

I've been looking around here as I'm new to this site but haven't found too many references to the impact of a spouse's ADHD on children in the family. My husband has ADHD and takes medication but it is a continuous roller coaster of manic enthusiasm and bursts of anger and at times verbal abuse directed at me and our children (for example, calling my son an "f*ing retard" to his face). Until now I felt my 4-yr-old son was too young to understand but now he's starting to have uncontrolled outbursts himself and seems scared to make mistakes (as of course am I, that seems well-documented on this site). My husband recognizes this is not ok and sometimes apologizes but doesn't seem to be able to control himself. In my mind you can't apologize to a child after saying hurtful things and have that assuage the damage. I feel so alone here; I feel pretty strongly that kids should be raised in a 2-parent household if possible but am struggling with what is worse for them. My 4-yr-old is a sweet and loving boy but I don't know if this home life is producing these changes in him or if he's also got "it" and I'm going to start seeing more and more manifestations. My 1-yr-old seems to have been born with a bad temper and I fear for him too. I think I have made such a mistake and now my sweet boys are getting the brunt of it both genetically and environmentally... Mind you, 95% of the time my husband is actually a great and very involved dad. He clearly loves his children. Has this been anyone else's experience, and what are you doing to try and fix it, if that is possible?