Big Hugs~

We have ALL been where you are at some point. Its quite easy to burn on doing this kind of work which isn't always rewarding. Add on if you have young children of your own and a husband who works a lot of hours. This winter has made things alot worse as well with not being able to get out as much that can add on more negative feelings.
I think that the others made alot of great suggestions. First of all sit down and make a list of pros and cons, take an honest look at your finances. I still do that once in a while when I am starting to feel burnt out and it always sends me back to this business.
If there is 1 particular family causing too much stress, let them go! Its amazing how the group dynamics can change.
Try and take time for yourself. I know for me that is very hard to do. My husband works alot of hours and I also have 4 other children, the older 3 have activities 3 evenings a week so its always a rush to get the dck out and have dinner and then I am home with my youngest who is 22 months old and quite demanding not to mention I am 8 months pregnant.
I also go with the flow quite a bit now and don't put alot of stress on keeping my house super clean or trying alot of messy crafts with the kiddos (all 18-24 months of age). If I have a high energy day I go with it and get as much done as I feel that I can. If its a low energy day, I lay on the couch with the kiddos and read and sing songs and watch a little more tv than usual. That is okay!
Keep in mind that there is a light at the end of the tunnel. For me its when this baby arrives and my husband will be off on parental leave for 6 months and the warmer weather will be here. One more month!
Big hugs to you!!!