Exhaustion

I just have no energy anymore. I will start out a week ready to go, ready to complete all kinds of stuff and excited about what I can get done. Then Tuesday rolls around and I am dealing with a second day of people going back on what they told me 5 minutes ago because something happened that made them look like an ass. And I will bear the brunt of the "well, you should have known to do X instead..."
Should i have? Really? When there was no training and there's no knowledge base to this job? I think I'm doing pretty damned well given I had only one week with the original desktop lead.
I fight sleep getting here in the mornings. I fight sleep driving home. And when I'm here it's a parade of shit people want done immediately without realizing in the big scheme of things that the server that's out in China ranks above the fact they can't print something out in color.
I'm so tired I'm making mistakes I haven't made since I first started this job, and that's beginning to upset me. I pride myself on doing a thorough job, but when you can't even THINK to focus a though...it becomes difficult to do the job well. And it's also been noticable. The boss will stop by and say "Just in a rush and a little overwhelmed?" Yup. Pretty much every time.
I'm so tired of being tired. I'm tired of hurting, too. That's begun to creep up on me since I started this job. The weekend will be renewing and fun and I'll be rested well....and then I show up on a Monday and it eats my reserves in all of 2 hours. I spend the rest of the work frustrated, stressed, sleepy and forgetful. When I get home all I want to do is throw food down my throat and go to sleep. Nevermind school. Nevermind writing or painting or sketching. I just want sleep.
This really isn't a way to live. I've tried adjusting my schedule in order to work better with everything and discovered it was pretty much pointless. I still have to get up too early. I still come home late.
I've hit this sort of mellow stage where I am SO tired that nothing that comes across my field of view really affects me. If a gunman shows up, I'm completely doomed. But for this brief moment I'm beyond wanting to go in the bathroom and hide just so I can get a break from the incessant work.
They gave me a raise recently, ( a whole dollar, better than can be said for anywhere else I've worked before) so I know they want to keep me around. But I just get SO beat up here... I don't know if I can keep taking it energetically, emotionally, mentally... *sigh* It's like trying to decide if you like someone enough to adjust your personality for them. I need to pay the bills. Do I adjust myself for this job and just keep screwing up and being sleepy? Or do I go elsewhere for a possibly worse position that will leave me wanting to come back here?
I dunno. I just know I want a nap more than I want a paycheck and I can't recall the last time that was true.