Neither of you are behaving reasonable to each other.
He's not being reasonable going AWOL and making you worry or the fact that you seem to not be able to have the opportunity for your own "letting the hair down" time (doesn't matter if you don't want to take it, sometimes it's nice to have the option). Fine.
But even the language you're using in your post there made me cringe!
so I thought ok I can live with not going... I was not happy about this... he's only been invited to the evening do but whatever, after a few disagreements about it, I got over it...
Checking with friends about whether it's acceptable for him to go to a close friend's event alone for perfectly reasonable logistical reasons, and then punishing him for it...?
It's not your DH's fault that he's been invited to a wedding alone, in fact that's sensible if they're on a limited budget/guest numbers and you've never even met the friend! It's not weird at all.
him going out after work (I'm a SAHM) is big source of conflict for us
Then you need to sit down and talk rationally together about what you expect vs. what he expects and come to a calm agreement.. if he says he wants to (or maybe needs to, for his career!) go out 4 times a month.. but you need help or want more of his time.. maybe you can agree on 2 events a month to make that work. Then he'll have to prioritise the important ones that he wants but also respects what you said you can manage. Don't try and discuss this when tempers are already flared up!
I told him he's blown it and can't go to the wedding... I offered a compromise of go but don't drink and instead drive home tonight
It sounds like you're dealing with a stroppy teen or step son or something there, not a partner with whom you discuss things or work with to make a household work..
the only way I got him to agree to that was by storming out of the house and letting him stew for a bit...whether or not he sticks to the agreement remains to be seen
Doesn't sound like he had much of a choice but to "agree" in vague terms tbh. You issued instructions and expected him to comply, and used unreasonable behaviour to do it - and now you're testing him to see if he'll "pass" - I'm guessing you'll give him hell if he "fails"?
Basically, it sounds like you're controlling and not very understanding of his wants (or, for work, his needs). You also seem to have legitimate grievances that you need to talk wiht him about, at a calmer point, and discuss how things can work better ovr the longer term - NOT when he's off to what's supposed to be a happy event for his friend and you've stormed off and ruined the whole thing.
You both sound unreasonable.