We homeschooling parents put a lot of pressure on ourselves. Society puts a fair amount of pressure on us as well. Do our children have the social skills requisite for success? Do they interact well with their peers? Are they learning everything everyone else seems to think they need to know? And....how are we going to teach them calculus?
First - remember that most learning occurs from a child-led perspective. That doesn't mean complete parental hands-off, but it does mean that when your child shows an interest in something, let them satisfy that interest. Are they interested in gemstones and crystals? Have them grow rock candy to see how crystals form. Buy them some interesting rocks at a metaphysical shop. Show them geodes, and maybe even go rock-hounding with them.
We just finished studying Galileo and Copernicus. Jared is very interested now in the solar system, stars, and telescopes. We'll go to the planetarium, head out to the West Desert here in Utah to look at the stars, get pictures of the planets for his room, make a mobile of the solar system.
The point here is that ... kids will learn. All a parent really has to do is give them the tools to do it. Homeschool doesn't necessarily mean "school at home" - and by relaxing about school, my kids have more freedom to explore what they want to learn.
Oh, and calculus? Learn it right along with the kids, find someone who is good at it and can teach it, use a homeschool co-op, or allow them to dual-enroll with the high school or community college. You don't have to know everything - or even very much! to homeschool effectively.
So relax! If you're putting any effort at all into your kids' education, odds are pretty good you're going to do better than the government schools ever could