This may seem contradictory, but you have to schedule the contemplation or peace-and-rest time as if it were an obligation. That is one thing that "sangha" can do for us, if we join in this effort with others; but other people come and go, and we have to figure out how to do it for ourselves. Rest and spiritual rejuvenation are necessary in order to do all those other things to the best of your ability; therefore, if we really ARE in the rest of it with all our heart and soul, we DO have an obligation to provide ourselves with the time and activities that will fill up the pitcher so we can keep pouring out stuff with integrity, honesty, and depth. Otherwise you end up pouring out nuthin'.

A lot of people choose very early morning to fulfill this obligation to themselves and the Creative Spirit: they get up at 6 or even earlier, and they just have a rule that those next two hours are theirs, no work, no calls, no e-mail, no working out - all that has to be scheduled separately; just meditating, reading, or the like. Gardening or some other quiet solitary activity works for some people too. I don't do well with the early morning thing; I sleep through it, so it's easier for me to save certain times on certain days of the week, or evening times. And I don't always do it, and then I feel lousy.

It's very important that you do NOT see this sort of thing as an indulgence. It is not an indulgence; it is part of being a human being. It is not avoiding "what you do," it is part of what you do. It is part of your "Work," as in "right livelihood" work.

I would suggest this as a start:

1) pick a time of day that this will work.
2) plan at least a half hour. An hour is better.
3) Write it in your planner. It's an obligation.
4) put aside one book or magazine or recording or something that you want to interact with NOT because it is related to your work, but because it is rejuvenating or related to your physical work. Plan to engage with that for part of the time.
5) spend part of the time being completely still. I would suggest meditating. Say a mantra in your head for 10 minutes. Watch your breath. Practice observing and letting go of your thoughts without judgment.
6) fill the rest of the time with anything that makes you feel fulfilled. That might be the book, or some combination of things.

And--

7) once a week, schedule one hour to do something completely unrelated to your work that just makes you feel happy / rested/ creative. Examples: go to a bead shop and stare at the cool stuff. Spend an hour at the Odyssey. Drive to Barnes and Noble and read books you have no intention of buying. Go to a museum. This is not a waste of time.

At UMass Amherst there was a huge greenhouse conservatory. When I was overwhelmed I used to walk up there, go in, and just sit with the humongous plants. I did the same thing at IU. It was great. It was rejuvenating. It cost nothing.

Just some ideas.

I firmly believe in a Day of Rest. It doesn't (for me) have to be a religious day, nor specifically a Saturday or Sunday, but I find that I need to recharge by stepping away from my work once a week. I can't always manage a full day off, but even a half day can do wonders.

I do agree with dharmonia that we have to schedule our rest as an "obligation." Yes, we OWE it to ourselves to care for ourselves.

But finding the balance? It's an ongoing process. Sometimes I get it right, and sometimes I don't. But that's ok. :)

I logged on to say (in different words) what dharmonia and terminal degree said, and they both said it beautifully. But I'm also of the school that believes good advice is worth repeating. :-)
What works for me is this: 2 things, Wednesday nights are scheduled as "my time." You may equate it with the locals going to church, because, while you're not going down to the Big Ol' Chapel down the street, what you're doing has a similar thought process and effect. One of the things I love about living in FP (and not the U) is that in the public schools we NEVER schedule anything on Wed nights because so many families have church.
You're right: because our work is so close to our personal essence (I envy the boyfriend quite often that he can punch a 40 hour week and then remove himself from work entirely), we're both incredibly blessed (where else do you get this much fulfillment?) and incredibly cursed.
On a personal note, I discovered "personal days" this year in my place of work. On approaching the principal to ask if I could take Friday off to attend an Irish Music Camp for the weekend, I was told "well, that's what personal days are for!"
:-)
They keep us sane.
So occasionally you might even schedule a retreat which has nothing to do with your studies. Also, we've had this discussion: martial arts is another good out because you have the benefit of letting go and simply being a student. Handing that control over to someone else for even an hour can be very emotionally cleansing.
Anyway, there's my 2 cents.