Balanced mom

I was contacted yesterday to see if I am available to come into work while another dietitian is out on medical leave. I was initially excited because I like what I do and I like to earn my own money. But with children, it is not that easy to just say yes and hop in to work.
Right now, I do not have balance between my life as a parent and my own identity otherwise. I am overwhelmed with my current situation, and although it is beneficial to be away from your kids, sometimes as crazy as it may seem, when you are overwhelmed it is harder to leave what is causing you that stress.
In terms of the day-to-day activities, I do everything for my children. Honestly, I do not want to become comfortable having a lot of help because if one day that help is not available, I fear I will be ill-equipped to handle the situation. Plus, I truly believe that my kids are my responsibility and I don't believe I should delegate the activities necessary to their life if I don't have to. For instance, I believe they should sleep in our home - they are my children and they belong in their own bed at home. I do not criticize what other moms do because everyone's life situation is different and their ability to handle that life differs from person to person. Not to mention, raising children is hard. I know it because I have them, and for that knowledge, I do not judge.
However, many times I believe other moms are much better off leaving a child with a family member for a day, putting them in school or day care, hiring a nanny, or getting a break otherwise. These moms have sanity. It seems moms with multiple children rarely do everything without help - and that is not a fault it is for survival and sanity and for patience-restoration. I told my husband jokingly, "This is parenting," pointing at myself, "this is what being a parent is all about - carrying on through the day, with mess in your wake, becoming more and more annoyed as the day progresses until you nearly want to kill them just before you put them to bed as early as the possibility for tomorrow morning's painlessness will allow!" I was kidding, but this is reality. It is difficult to keep children happy at their various ages, keep them safe, clean and fed, while always remembering not lower your standards realizing actions in the present correspond to learned behavior in the future. This is the hardest job I've had and the most important job I've had. I am not perfect but I care immensely about my children and I go to bed having done the best job I can, while asking for the patience and energy to do it again and to improve my shortcomings.