I think you need to learn to advocate for yourself, because nobody else is going to. If you need to stop to eat breakfast, tell your colleagues, “I need to stop to eat breakfast”. Don’t expect them to guess your requirements.
Ol’ Max uses his time efficiently.
You need to be careful with people like Max.
The thing about Max is, he is incapable of assigning a value to other people’s time. I would say he assigns a value of zero to it–but that would be overstating it because Max does not consider other people’s time at all. If Max could trade ten thousand hours of your time to save ten seconds of his own, he would.
It is not Max’s fault, exactly–he was born with a cognitive defect preventing him from doing this. As such, when it’s pointed out that he’s wasting other people’s time, he gets angry and confused. For him, it is like doing elliptic calculus or some other math that is beyond him. Worse, everyone else can do these calculations without trouble. So have a little sympathy for Max, here.
In short, you need to stay away from any situation where Max can benefit from your time, because he will make that trade without thinking. Bow out of interminable dinners; arrange your own transportation; set your own schedule for meals and activities. If your paths intersect with Max’s, be friendly. But under no circumstances should your schedule be beholden to his.
People who go on a work trip and work? 
Didn’t seem like he was working much on those late nights out or when stopping at the store just before the plane ride.
That said, I am with Max regarding checked bags for a 4-day trip. C’mon.
They were work, schmoozing with people in other branches is work/networking. He only went to eat instead of waiting around for the others to go through the baggage check.
Both dinners, according to the OP, were company dinners with coworkers where they talked about work, then on the way back to the hotel Max kept talking about work. Honestly, if one considers a work trip to be about actual work, Max is the only one who comes off well in the story.
(maybe he wanted to stop by the store to grab a snack for the plane because he knows he gets in a bad mood when he’s hungry? 
)
I had a client who viewed any time spent waiting in the airport as a horrible waste. His ideal trip involved him boarding just before the closed the door.
He missed a few flights.
So I always just made my own travel arrangements (especially rental car or taxi) based on whatever was convenient for me because I knew I couldn’t count on him.
This sounds to me like maybe you just don’t travel much? I wouldn’t dream of setting off on a trip like that without a couple of power bars and caffeine pills in my hand luggage. I know what happens to me if my protein gets too low or if coffee is unavailable. I also have a book, some yarn, and a crochet hook in case I get stuck somewhere. Boredom kills.
And yes, Max is a dick. He was ridiculously unconcerned with the needs of the two people in his care. I suspect that he was not thrilled to find out that you WERE to be in his care, and may actually have had plans of his own which didn’t happen due to your needs; like going to bed early the first night.
I also will not agree to any work trip outside of downtown Manhattan that doesn’t include a rental car. One time stuck in a suburban hotel without a restaurant was plenty for me. But it sounds like you don’t drive in general, so taxis ought to be your go-to. I agree with whoever said above, as soon as Max admitted that he needed an hour or more you should have called yourselves a taxi.
As for the meals, this is a work trip, will you not get them reimbursed? I’ve been in that place of just not having many resources, and having that be a real burden. But you feed yourself and get on with it. Fill out your expense report immediately and get your money back, don’t let it wait. It’s been my experience that a polite visit to the accounts payable clerk in charge is generally met with understanding and swift reimbursement.
Overall though, you need to do better preparation. Before I left on that trip I’d have already checked the hotel restaurant hours and what was in walking distance of both hotel and venue. I’d have packed the aforementioned snacks and reviewed the schedule with my traveling partners. For longer trips I’ve even been known to FedEx my big bag to myself at the hotel so I don’t have to schlep it through airports.
But I spent a whole year on 80% travel once, so you learn the ropes as you go. Being a fellow anxiety sufferer, I will say there are many ways to give yourself control, and they all help immensely. Plan ahead.
Just thought it’d be good, for anyone scrolling through, to read that twice.
As someone whose default setting is “Pfft, plan ahead? That’s what boring people do.”, I’ve been bitten by that more than once.
So now, well ahead of any trip, I ask myself “Well, what could go wrong?” (said for some reason like an old Jewish comedian, with a shrug). Then I think of all the things that could go wrong:
• Luggage lost? I’ll cram everything in a carry-on, or at least have clean undies in my bag.
• No in-flight snacks that don’t cost more than a nice dinner? My bag is FULL of Clif bars and trail mix.
• Stuck in a strange airport? My bag’s also full of magazines, a sketchbook, and a real book. And my iPod’s full of music and movies.
• Stuck in a strange airport for days? (if you fly Spirit, they’ll cancel half of your Thursday flight, stranding you at O’Hare, and say “We’ll book you on our next flight… Tuesday!”) Have a mental list of activities (took a shuttle downtown, walked through the Art Institute and found some Chicago deep-dish pizza… mmmm…)
I’m now famous for having a Plan B, C, and D. The family will sometimes ask “We on Plan F yet?”
This is all so totally ridiculous. Max isn’t some buddy BPC went on a road trip with. They are on a business trip and Max clearly seems to be senior to him in the company even if he’s not directly above him.
Why didn’t you post this in MPSIMS?
Since when is being senior an excuse for poor treatment of others? Granted, in some companies it might be a prerequisite for promotion.
BPC seems to have no obligations to Max. I see no reason why BPC shouldn’t simply taxi around on his own.
My boss thinks it’s definitely a me problem, that this trip was a catastrophe for me because of me, and that if I want to keep my job I need to step it up.
What did he say you should have done differently?
How was it a catastrophe? You were miserable on the trip, but, “catastrophe” seems a bit extreme.
Other than leaving that dinner early, what is he saying was a particular problem? What does he say you need to “step up”?
Not been mentally ill? Plan better? I dunno.
Also both of the other senior IT members have written me off. Yay.
Well, I wouldn’t be surprised if everyone BPC interacted with on the trip noted his anxiousness and annoyance with everything and that got back to his boss.
That BPC needs to stop being an immature whiny bitch who thinks the world revolves around him would be my guess.
Ouch.
Sorry, that’s got to add to your general level of anxiety. But something like this gave me a “shot across the bows” and a chance to change my life. I started planning ahead, doing a quick spreadsheet of everything I’d need on a project or a trip, and getting those lined up ahead of time. (Yes, even meals and rides)
AND I was open and completely honest with my boss. Told her how my personality quirks had tripped me up, and how I’d make sure I could minimize those in the future. So I started emailing those spreadsheets to her before a project/trip started, and she’d either ignore them (which meant all was well), or ask “What about X?” and I’d come up with an “In Case Of X” plan.
I ended up with a promotion out of it (after a couple of painful months), I think because I was the only minion admitting my problems and working on them (and around them). So in the boss’s mind, I was making more progress than the “More Capable” coworkers who stayed at the same level of Adequate Competence.
ETA: I just went back and read your rants from during the trip. This also could be your chance to quit, and find a better job!