Is there such a thing as too much service?

I have spent 94 hours from last sun nite to today doing service for non-family members and i have another 17 1/2 hours comitted to do until Sat morning at 1am. I am thinking of all the things I NEED to get done for my family & home that are very important, but the service projects are time sensitive. I also haven't volunteered at any of the kids schools yet this year and Ethan really wants me too. I have also been sick for 3weeks with a sinus infection & bronchitis. I won't be putting in 90 hours of service (running my friends daycare & cleaning & organizing it) like that again for awhile, but i still do over 30 hours in service work a month (does not include a couple hours of volunteer time at school - when life gets less crazy). I enjoy doing service, but feel that I'm not getting things done at home that I want to do. And I do say NO alot (and feel guilty). So, how much is enough and
how much is too much?