Be careful what you do through your work PC. You may not care at this moment, but this could come back to haunt you. I've seen people terminated for "misusing" company resources (i.e. Internet surfing).
Strive to maintain a professional attitude at work. I would work hard now because you may need a good reference from your current employer for the next job you want.
Find an outlet for your stress on a daily basis. Exercise (a walk at lunch) helps. Make a vacation countdown for your desk, even if it's on a post-it note pad (not one from your employer -- buy your own). It will give you something to look forward to.
Find ways to take a 15 or 30-second vacation. Find a hideaway -- even a bathroom stall -- relax and recall a pleasant past vacation for a few moments. It can help ease the stress. Don't let the stress pile up -- if you need a quick break, take one. If you can't, try several long slow breaths -- remember calm blue water, slow ocean waves, drinks with little umbrellas.
Finally -- smile -- they'll wonder why you are with all the work and it may drive 'em crazy.