Take your vacation; take all of your vacation. And, when you take it, don't call your office (or have your office call you), and don't look at your emails. In fact, try leaving your cell phone, laptop, or any other mobile device at home.
Some people (foolishly) brag they don't take their vacations. Don't be one of them!
You need the break; so do the people working with you. Besides, how better to see how your staff members can perform than to let them perform without your oversight? Taking breaks, of course, will help you keep your perspective, but those breaks will also give those working with you a new perspective.
I never in my years as a college president left any vacation days on the table; however, I never felt the least bit guilty because I never missed a day of work in those years, either. Of course, my foolishness resulted in others missing work, since, even when sick, I would go to the office. In fact, to keep my record in tact, I even stupidly showed up at work in the afternoon following a hernia operation.
I love to travel. When given the chance, I tend to travel off -- way off -- the beaten path. For me, therefore, it was easy to follow my advice of never being in touch with the office. In fact, only once in 24 years as a college president did I ever get a call from the office. In that particular case, I had to take the call because my sign-off was required to settle a lawsuit.
You may feel you're indispensable. You clearly are not. Set aside your delusions and recognize the institution was there long before you arrived, and it will be there long after you depart.
Getting away from the office periodically will help improve your mental and physical health and the health of those with whom you work. So, take your vacation -- all of it.