I feel your pain mama! Our little guy is starting Kindergarten in September. We're working on a plan, I'll outline some of our solutions below:
Home daycare for afterschool. Dh goes to work later, so he will get him on the bus. But afterschool ds will get off the bus at the corner near the home daycare we chose, which is right on our street. She's open year round except for Christmas week and the major holidays that we're off work anyway. So school breaks we'll have the option of having him there for full days (we'll pay a full week rate for all week full day or that rate/5 and pay just for the days he'll be there). Same with snow days. And for half days he'll just go to her home earlier. (This is a licensed daycare, we verified her credentials and complaint history...there was none...with our licensing bureau. We love her and her setup is great, she's got other after school kids coming on the same bus as well.)
Sick days we generally split our days. Dh will go to work super early, and be home around noon. I'll go in at noon and stay late. Thankfully we're able to do this on occasion without a problem. Sometimes because of work commitments (like Mondays are near impossible for me to be off because of payroll, so he does full days those days...if he has a meeting or conf call I'll stay home all day).
Summer will mostly be covered by a camp in our town.
I have an uncle who's retired and will back us up on some days to help out.
My mom is out of state but will take ds for a school break and/or a week in the summer. And she'll come for a long weekend when he has a Mon or Fri off but we don't.
My MIL is local and on occasion she'll take a day off to spare us some vacation time. Same with taking time off to spend with ds in the summer.
If you can get to know any SAHMs who might be interested in earning some money for school half days or snow days, etc...that would be a good solution since you don't have the family nearby that we do. Or start looking for a HS student in the same town who might be willing to come over for snow days. That would help.
Good luck!