Why am I extra angry now?

My husband and I have been married for well over twenty years.  From the very beginning of the marriage, the only thing he has ever done in any real way is earn a paycheck.  If I asked him to do anything, it was because I actually could not do it.  We have multiple children with adhd, too, and he did not help with any of their care.  I remember with our final baby, I was desperately needing some help, and when I asked point blank for him to commit to helping with the baby in the evenings, he became very angry and refused.

He is now, suddenly after 20+ years, doing one singular task once a week.  He might sometimes do it twice a week.  He committed to only one day, so the second day is a bonus.  I didn't ask him to do this thing; he offered. 

Whoopee.

I watched him do it in fits and spurts.  He seems to finally be mostly consistent.  I do not feel any kind of happiness over it.  I assume my guard is still up.  But if I have any feelings, it is anger.  The thoughts that accompany the anger are things like, "Had to wait over twenty years for this tiny bit of effort.  This is pathetic."

I have worked on my anger over past hurts.  I have been doing well on that front.  However, now I am angry with him for this small effort.  

It is silly to be angry.  If anything was ever going to stick, he would have to start small.  He has definitely checked that box.  And it couldn't be a very impactful task if he didn't follow through.  And, because he isn't medicated or doing anything to manage his adhd, this is a definite win.  And yet I am angry.