Suzi,
I know just how you feel. While I was running my own home daycare I was actually advised to get a "light box" because my doctor thought I might have SAD - seasonal affective disorder. You sound just like me...tons of energy all spring and summer, then drop off like a fly in the fall and winter. The light box cost me about $200, but let me tell you - it works! I sit in front of it for about 0 minutes in the morning while I eat breakfast and put my makeup on at the table. (The light stands on any hard surface.) If I am really low, it sit in front of it for another 15 minutes in the late afternoon until doing it just in the morning seems to hold my energy up all day. The light gives me the missing light only the sun can give me and it really puts a better hop in my step. I found my light at a medical supply store, but you might want to call your doctor/insurance company to see if one can be prescribed to you and at least partially covered by them. If not, I still couldn't emphasize any stronger how different my winter "self" is now with it and I would never go back - no exaggerating at all.
Good luck finding your smile,
A.
P.S. Here are a few websites with fun at-home crafts and activities that might have some new ideas for you.
familyfun.com
mothers-home.com
preschoolcorner.com
P.S.S. Finally, here are some other things I did with my kiddos to keep us busy during the winter.
-Yard/House scavenger hunts
-Shaving cream fingerpainting on the table (FUN!)
-"Fingers Only" lunch - messy, but great - try mac & cheese, etc.....slimy and fun!
-Jammie Day - I invited all daycare kids and my family to wear them all day and we watched movies, etc.
-Find a bookstore that does a preschool reading hour. Borders here does a story, art project and snack for free once a week
-Go visit a willing and able elderly neighbor who would like the little bodies around for a 1/2 hour. It'll bring a smile to their face and give you some adult conversation/time out of the house.
-Put on your own daycare exercise class. My kids LOVED this. I was the "instructor" and we did stretches, jumping jacks, etc. together. It will give you a good endorphine kick to get rid of some blahs, too.
-Freeze dance - We would silly dance to a fun kid cd and have to freeze when I pushed pause. Another good chance to get some endorphines, which are clinically proven to kick the blahs.