To Sunday school or not to Sunday school

Okay, this Sunday school thing is really getting to me. I feel like I have no time to commit to helping in our church's children's program. But at the same time my husband and half of the church are constantly reminding me that it would be wonderful if I could help. I have no idea why they seem to "have to have me". I think honestly, that it is just because I homeschool and they probably feel that I have a lot of resources for the curriculum. I just feel strapped for time. DH is probably going to be starting a job this week and it will be difficult to adjust to because it is a different shift than what we are use to. We also have endless gardening and homesteading jobs as well. I don't know what to do. If anyone has any advice please HELP!!!! The class is around 15 kids ages babies to around 10 or so.