Questions for ADDers

My BF is adhd and we are in a really good place in our relationship.  On the weekend he got really frustrated because he had left a package behind while shopping.  He blamed leaving the package on my interrupting him when he was concentrating on something else (which I did) and had a bit of a hissy fit.  It genuinely didn't upset me.  I recognized his frustration for what it was and we talked it through without it snowballing.

Later that night he came to me and to me and asked if I still loved him.  I responded of course I do, why do you ask?  He said because he behaved so badly earlier.  It broke my flipping heart.  He is such an amazing, caring, sensitive, loving man.  How do I help him not feel so badly about himself?  What can I say or do to ease self criticism?  What does he need? to me :)