It can be overwhelming at times. I can imagine it being more difficult with an older child than these young ones. We have hit the February Funk here. I was getting burnt out so, with the exception of things outside teachers have assigned, we are doing our dinner studies (kids eat and I teach) and our hands on geography crafts that were prepped in the fall. I literally do not have to think for the crafts. I simply let the kids go at it and take a bunch of pictures for scrapbooking. It's a break I tried to avoid - even though I planned for it knowing that every year we start to croak about now and come back to life with the warm weather. I love afterschooling and most of the time the kids and I are enthusiastic about our plans. (My eldest will tell me if she thinks something is less than stellar) I don't think I could ever teach them everything I want to, even if we were homeschooling. We do our best and call it good enough. My enthusiasm is waning at the moment so we are kind of on a break. Kind of.....
Editing to add: At one point last year, my husband who is a former PS teacher, told me that sometimes "You just need to move forward regardless of whether you covered everything or not." He said that there were times when he had great plans for his classes and what happened was more skeletal than what he envisioned. Sometimes the lessons here are lush and fleshed out- but if they are skeletal I try not to stress about it. The kids seem to learn regardless.