So, your wife's a bitch, and she's especially a bitch when it comes to logistically organizing the family.
You're too used to deferring to her frame, letting her lead an effort like packing for the family, and you're not nearly skilled enough as Captain to lead it yourself. She's a bitch, but some of these tasks she's asked you to do, they do need to get done and you wouldn't have thought of it yourself. So that's a tough position.
Let's go back to that night you were a photographer at your friend's wedding. What differed about that night?
You were competent. Presumably you have some kill at photography, which is why a friend would you to come take photos of their wedding. You were demonstrating an actual skill, something your wife or a lot of other people couldn't do.
Separated from your wife and kids, you had no family logistical responsibilities. All your wife could do was nag you to come home. She couldn't nag you actually do anything.
The problem is this is an uncommon scenario. So how do you manufacture this one in your real life?
This is a particularly Dark Triad suggestion. But your wife is a spouse abusing cunt. I didn't comment on your last post because I consider that physical violence, "go directly to divorce, do not pass go and collect $200." Only because the risks are too great. At some point she'll hit you again and you may defend yourself or react abruptly and hit her back.
So if you're not going to do that, I'd suggest this.
On your vacation trip... Faint. Yes, faint. Maybe in the evening when the kids are in bed. Take a walk with your wife and at one point, collapse in mid walk.
Go out cold for 30 seconds. Then come to. Your wife will probably be somewhat hysterical. Ask her what happened. Tell her it just felt like you suddenly got tired and blacked out. You do remember falling to the ground but that's it. Then say, "shit, I think this is one of the things the doctor told me about."
She'll continue freaking out. What doctor? Tell her never mind, you don't want to worry her, you feel fine, you just want to continue the walk. She'll keep saying she wants you to talk to her. Tell her you had sharp pains from your jaw that seemed to "spike" from your jaw line up to the head. Doctor said it was probably just bruised nerves and made a follow up appointment next week.
She'll ask more. Did he say you could faint? Why did you have jaw pain? Just say you don't want to talk about it. She'll still persist. Just say, "look, we both know this could have been caused when you hit me. I don't want to think about that anymore. Do you? I just want to go back to enjoying vacation. When I go to the doctor I'll know more."
Get back home. Schedule a regular physical with your doctor. Might as well get one anyway. Go to the appointment.
Your wife will be, once again hysterical, and what to know what the doctor said at the appointment. Tell her he asked a bunch of questions. He asked what caused the injury. He asked if I've been under a lot of stress. He asked a lot of questions about your mental health, actually. But main thing is to just get exercise and avoid stress and call him if you continue to feel these "shooting pains."
Your wife will be all, "well what did you say when you answered those?" Just say, look, you clearly felt you were in the right when you hit me. So you feel more comfortable just dealing with the consequences myself. Anyway, then say you need to go to the gym and exercise. Doctor's orders.
The purpose of this charade is 4 fold.
Remind your wife you have two little kids and she's still very much in the Security phase. You could die, just like we all could, at any minute. She should probably not take you for granted.
Doctor said to avoid stress. Internalize this. This is your new frame. If your wife starts bring bitchy, just leave the room. If she says why are you being an asshole emphasize that you just need to remove yourself from stressful situations, and she's really good at creating those.
hit the gym. Doctor's orders. Improves circulation, reduces stress. Your wife would probably nag you to death if you tried to start a gym routine and your frame may not be strong enough to withstand it.
You are now OI. Your brush with passing out has made you realize life is short. You want to live life to the fullest. That means not tolerating negativity and conflict. You want to spend time with friends, do things with your kids, enjoy life. You don't want to spend your evenings and weekends getting yelled at by your wife for yet another perceived deficiency you've presented to her as a husband or father.
The next time you have another major family event to coordinate, go to your wife a full week early with a pen and pad. Say you've a list of things that need to get done. Here's the list - put gas in the car, bring luggage down from the basement, etc. To minimize stress, you want to handle these things now instead of the night before. Ask her if she has any additions, otherwise you'll be doing those things.
Then say, cool, I made a list for you too. You can use it if you want, you think it'll make things less stressful for her too. And just hand it to her.
You've just flipped the script. Now you're the one giving orders, she's following. Because when you give orders, things are calm, well-executed, and prepared well ahead of time. It's not "did you move the car seat from the SUV yet? Well why the fuck not!?"
The whole faking a fainting episode and a cranial injury is absurd, and involves a level of deception I normally wouldn't recommend. But your wife is a stone cold cunt, and your marriage is pretty much burning up in a trash fire anyway, so I don't see what you have to lose here. Doctor patient confidentiality should ensure she doesn't really find out your condition is invented. Nor will she be that eager to pursue it, since it means admitting that this condition may have been caused by her hitting you, and she probably won't want to revisit that.
Like I said, this is manipulative, machiavellian shit. But, I suppose, one redeeming part about being the last rung on the ladder is that it doesn't hurt much if you fall down.