Ooch, ouch, aahh

Sometimes a job I dislike motivates me to write. I think a part up my brain jumps up and reminds me that if I am successful in my writing career, I can get out of this rat race. At least partly.
But this particular job leaves me too mentally and physically exhausted to want to do much of anything. Mentally because all day long I focus on ridiculous little details until it drives out all creative thought. Physically because I SIT ALL DAY LONG.
You think that's not physically exhausting? Have you tried it before? Yes, I'm a writer. And I've had desk jobs. But they usually involve jumping up and down fairly often for meetings, filing, dubbing, whatever. But I don't move here. I drink water constantly just for the chance to get up and get it, and then the chance to get up and pee 20 minutes later. I spend my lunch hour walking around to work out the kinks in my body. By the time I get home my shoulders ache from un-ergonomic typing, my eyes are tired of staring at screens 12 inches away from my face, and my back is a painful rod of steel.
Thus the lack of desire to sit at another desk and type.
I think if I am really determined (which I usually am) I will figure out how to write during my lunch hour.