Am I Ready For This?

Yes, this is very uncharacteristic of me, but here is my 2nd post in as many days! I'm just feeling a little angst, and thought if I put it down in words, I might feel a little better.
I walked into an office yesterday and submitted my resume to apply for a job. It was a very surreal moment for me. I have not felt like that since I graduated high school and applied for my first job, almost 20 years ago! Okay, now I feel old, to boot...but back to the issue at hand...I am not sure that I'm ready for a 'real' job. But after being out of the work force for roughly 10 years, I'm not sure that I could do anything to adequately prepare myself, either. I had a job that I did from my home office in the last few years, but that was different. No commuting, no co-workers, my boss was my hubby, work on my own schedule just a few hours a week--that kind of different.
Mostly, I'm scared of how me getting a job outside the home will affect my kids. My hope is that any job I might get would allow me to be home most of the time that they are not in school. I know that's a tall order, but so far I'm not desperate for $$, and I think I can hold out for it. Having a little more income was what initiated the whole idea of me getting back to work, but now I'm feeling more like this is something I have to do to re-introduce myself to 'the real world'. I can't be a stay-at-home-mom forever, and the longer I put it off the harder it's gonna get. But it has been my mission in the last dozen or so years to be there for my kids whenever they need me. It's hard for me to let that go. I have to remind myself that kids are resilient and adjust to life changes much better than most of us grown-ups do. Right?
But then, there's the issue of being under-qualified and inexperienced. Is there really anyone out there who would want to hire me, based on my lean resume? If someone did give me a chance and hire me, could I cut it, or would I be a disappointment? I know where I worked before the kids came along, I was good at what I did, and my co-workers always asked me after I left when I was coming back cuz they missed me. But that was a long time ago.
Anyway, by the way I'm carrying on, it sounds as though I'm going to work tomorrow! Well, this job I applied for would start in less than a week if I got it, so maybe that accounts for my high anxiety. I actually applied for the same posting a few months back, but I sent my resume in via email (because I was too close to the deadline to bring it in personally). Somehow, that didn't feel as stressful, but I didn't get the job then, or even an interview, either. I think I didn't really have time to think about it then either. Time to think about things has always been bad for me.
Anyway, I should probably get off-line so that if someone's trying to call me for an interview, they can actually get a hold of me! How's that for optimism? A wise woman once said "fake it 'til you make it". I'll try to keep that in mind.