Okay I'm going to try to take a crack at this but this is just my hypothesis. I'm obsessed with psychology and self observation so here goes:

Your boyfriend has some kind of abandonment trust problem or he's experiencing some bad level of sensory input or confusion. I'm going to try to offer an insight into the possible logic behind his reactions (not that they're healthy reactions):

With the gas card it sounds like he was planning on spending the money and he was trying to make sure you would have gas which was a pretty bad call on his part. You shouldn't submit to him so much when he acts that way and try to push back a bit. Aspies can take some shove back especially if they're infringing upon your rights and messing up your finances.

The milk thing probably occured because of sensory input in the grocery store. Aspies are like toddlers sometimes- if you tell them you're only going so far and then they suddenly have to take even longer in the store they have little meltdowns or temper tantrums. You should recognize the tantrums as not being your fault whatsoever and try to just not talk to him until he calms down. I have to do this with my partner when he has meltdowns and when I have them I need the same. You can't let a toddler push you around and it's kind of the same way with aspies. They don't have the cognitive function to see past themselves to the way others may be feeling so if they act out you need to gently put them in their place like you would a child.

Time outs work, abandonment or threats of abandonment will not work as they cause shut downs and most aspies would rather be alone than in an insecure relationship.

You're right that your relationship should be about working as a team. Even in hard times you should still show empathy for eachother and he's not giving that to you. Aspies are capable of empathy you just need to break through their emotional walls.

My partner and I are both aspies and quite successful just by very clearly communicating as much as possible and when something is done that is uncool it's spoken about immediately and resolved.

I'm sorry you're going through this- I kind of do the correcting thing a lot and this gave me a bit of a stomach lurch I hope I'm not this bad. I can keep myself in check I believe with mindfulness and self awareness your husband should do the same. He can't walk all over you disability or not.