When is to Much to Much?

Last night I received an e-mail from someone regarding a volunteer group that I have done on and off for the past 7 years. It is the town wide women's group that helps those in our town and surrounding towns through fundraising. It is a great group of women and it is a good way to help others with a group of supportive women. The e-mail was regarding my membership this year as I had not paid my dues. I had not paid my dues on purpose because I didn't know if I could do it all. Siri is going to a new school this year and is going to need extra support from me and from Travis. Andy is going to first grade this year and is going to need me more as well as the preschool board I am on and finally my running. (I also have 2 other children). I thought about the e-mail, I talked to Travis and I thought about it for about another hour. At that point I had made my decision, I could not do it this year. Many times I say yes to so many things and then get totally overwhelmed and don't feel like I am doing a good job on anything. So many times we as women and especially stay at home mom's feel like we have something to prove, but who are we trying to prove anything to? Ourselves? I don't know what the answer is, but what I do know is that I had to take a step back and think about myself and my four little chickens. I admit it I can't do it all.