Which job?

So, I have this new job. And I may or may not hate it. And equally I may or maynot like it more than my last job. It was only my third night tonight and I got off early, but I do nothing but bust my ass the whole time I'm there, and I'm a pansy and it wears me out. Phisically it's exhausting and mentally it's exausting. Between working non-stop and being on my feet the whole time, learning how things work and what goes where and in what and how much of what to do what with and why this is all done, I feel as though I'm not going to learn it all, and will just suck at this and end up getting fired. I mean my crazy manager just fired someone who was an amazing employee because he called in sick and she didn't believe he was sick. So yeah....I"m just tired and feel like dying. And since I got this job I have barely talked to God at all. I feel like I'm trying to fit 48 hours in to every day and eventually my world is going to expload.
As you can see, I'm pretty frustrated, and I don't know why, but I need to calm down before I give myself a heart attack. Please pray that I get my crap under control.
Thank you.