Anyone feel overwhelmed by the amount these kids have to learn

My son has high functioning autism and can do math on his head at a 3rd grade level. That being said, I was reading over what they're being taught this month. How to add and subtract double digits. What? My bonus daughter is also in kindergarten, same school, different class. Her English scores came back at 40% and her math at 50%. I've always thought she was above average academically. So now I'm trying to spend an hour every day teaching her, while spending an hour with my son (he processes at a much faster rate as well as I'm more working on his sitting down and listening as that's what his IEP is focused on) as well as I read to them for 30 minutes. I just had to quit my job as teaching them, focusing on my own school work ( I'm in a medical program) and keep this home clean is absolutely exhausting me. I feel bad so much for these kids. Mind you I spend an hour teaching them because I don't want them to just learn sight words so I'm teaching them how to properly pronounce and sound things out, how to read the page without pictures, etc.