Don't Work Hard, Work Long
Yes, you have to work hard from time to time (like when you have to cram for finals). However...
99% of the time you shouldn't be working hard.
Work should never really stress you out.
That's a stupid way to live.
If it's hard, then you probably aren't cut out for it.
And if you don't like the people you work with, then quit.
Instead, just find an occupation that just works for you.
Work should never feel like a struggle. It should feel like something you just do between breakfast and dinner.
But do put in your time. Put in more time than the others.
Put in the hours and you will get your rewards.
P.S. In the theme of not working hard, put in the work but make sure to take plenty of breaks. Whether they be naps or mindless activities, the science shows it'll help you get more work done that day.