Explosions of extreme Anger in my partner, and my despair

I just joined this forum after my adult daughter was diagnosed ADHD and shared info that made me think that my husband is ADHD.  Classic ADHD/non-ADHD marraige... 35 years (plus 7 years of dating before that.  My husband is a creative and lovely person who, to the outside world, is the utmost gentleman; life together has been a series of roller coaster rides where, when I ask for more participation in family responsibilities like managing finances, planning for retirement, shopping and household projects that require planning, the conversation devolves into glaring at me, defensiveness, physical expressions of anger(towards things, not towards me) and threats to leave me. Last fall, his anger came out in the workplace and he was fired by a long time client.  He doesn't really think he did anything wrong in that situation, because he "didn't swear, didn't direct anger directly at the supervisor", but he did storm out.  I realize that this is probably what I experience from him, and he has no idea how abusive it feels.  I think this behavior was modeled for him growing up.  I am fearful of talking about important things because I fear it will devolve into extreme behavior.  As a side note-- his parents have both asked me to handle the responsibilities of being a trustee/executor, one for a Special Needs trust for a disabled brother; the other was to be executor of my mother in law's estate.  Mother in law had a stroke 3 years ago so I became her POA and financial manager; Father in law just passed, and in addition to the grief, I now have full responsibility for managing the Special Needs Trust.  All because I am the "capable" one.  I'm "good at these things".  I just want to scream...  We are finally getting couples counseling and I have mentioned the idea of getting screened for ADHD but no action so far.