One bit of advice I would personally give is to remember that work is just work.
You will have responsibilities, deadlines, arguments, critisms and one day you might find yourself anxious and stressed out. When that happens, it's nice to remind yourself that the critical bug or whatever you're working on is meanigless in the grand scheme of things. No matter how passionate you are about your company, your personal life and principles should always come first.
It sounds obvious but humans tend to forget that kind of stuff.