First, acknowledge that it's not your job's responsibility to provide you with any of these things. Your job doesn't have to provide you with meaning, or with attractive and intelligent and compelling coworkers, or with a spa-like work environment. All your job has to provide you with is a paycheck, and everything else is negotiable. It's up to you to demand, take, or find elsewhere, the other things you want.
Order a standing desk and foam pad and expense them. Don't ask, just do it. Take fifteen minute breaks every couple of hours. Don't ask, just do it. Pack a healthy lunch every morning, take time to make yourself something nice, package it up attractively, then walk to the nearest park to eat it, every day, taking a full hour or 90 minutes to do so. Don't ask, just do it. Bring a book and leave your smartphone on your desk. Show up at 9, be at your meetings on time, get your work done, leave at 5. Don't ask, just do it. Read "How to Live on 24 Hours a Day" by Arnold Bennett. You have eight more hours in the day that you're not using wisely if all you're talking about here is your day job.
And all of that is well and good, but it won't fix the root problem, which is understanding why you're in a day job in the first place.
A day job is two levels of abstraction which you have chosen to participate in, because it supposedly beats hunting wild animals, sleeping in caves, risking getting eaten alive or dying young of an injury, and having to literally fight for a mate.
A day job has its down sides: you are twice disconnected from the "real" activities that biologically keep you alive and make you feel alive: hunting, eating, having shelter, procreating. You don't forage for food any more, you sit at a desk and earn a paycheck, and then you go buy food. You don't even have to budget more than a week or two, because, hey, there's that next paycheck.
Freelancing, at least, is an abstraction only one level deep, because you forage for clients, and you have to budget extremely well to survive client famine periods.
I'm not saying quit and go freelance. I'm saying understand why you're in the day job, put it in the right context in your life, and realize that it's there to support your search for meaning, socialization, and health in the other eight waking hours, and other sixteen total hours, of your day.