When I grow up...

At the moment, I'm sitting at my computer with 3 children playing on the bed behind me. I know that I really don't have the time to be writing this, but I'm making an attempt to "tune out". I know...very responsible.
I'm not actually expecting anyone to read this, other than a handful of family or friends. But I feel like I need an outlet and this happens to be it. I've decided that if no one is really going to read this, than I can be absolutely honest, right?
I imagine I'm not alone in this, but I'm constantly struggling with finding my purpose. I believe in God and I pray that I will do what it is that He wants me to do. But I don't find myself to be someone of much insight and so I struggle daily with questions like, "Am I doing the right thing?"..."Am I making the most out of what's been given to me?"..."If I died today, have I lived a full life?" In trying to answer these questions, it only brings about more questions. I often wonder if I should have finished college, should I be working outside the home, should I be homeschooling the kids, should I be trying harder to be like Martha Stewart(without the jail time)?
As mothers, I don't think we ever feel like we could do enough for our kids. I sometimes think all I can see is where I'm "failing". I love my kids, I play with them, read to them, take care of them, encourage them. But there's always more I could do. Having an Autistic child doesn't help. Because the answer to that is yes, there is always more I could do. I don't respond well when someone tries to make me feel guilty about something. I know that I can guilt myself enough without having anyone else's help, thank you very much. In an attempt to ease all my guilt I find that I spread myself too thin. I figure if I'm not a very good housewife then there'd better be a good reason for it. So I have a small craft business, and I work on a lot of projects and events at church, and I babysit 2 kids(down to just 1 now). I couldn't possibly be great at housekeeping because I'm too involved with "important" stuff.
Why can't it just be enough to be taking care of my family?