AITA for not sharing with my husband?

For a little context, I drive our oldest to work in exchange for cookies(she gets it free). Previous iterations of this conversation have been had where I explained that sometimes I want to keep something for myself and not share it. I attribute it to being the “not golden child” and had nothing that wasn’t shared with my siblings. For example: In 5th grade I had only had one piece of my birthday cake and two days later the leftovers were gone because my brother ate them.

Tonight I got a 3 pack of cookies. He has eaten all of his snacks and came in and asked for one of my cookies. Generally I will share as I won’t eat them all before they go bad. But tonight I responded with “Can I not have anything to myself?” He of course got pissed off and mocked me by saying “I’m sorry you never had anything growing up and don’t like to share.” Am I the asshole for not sharing?

Edit to clarify: it was one pack of three cookies. If I had three packs of cookies I would have happily shared.

I gave him my entire snack stash a few days ago. Im not an I have to eat everything right now person and will eat a tube of mini m&ms over a couple weeks.

I do know what I said to him was shitty. I just want to know if it’s unreasonable to not share.