I am looking into possible resources for these topics myself, but I do have a suggestion for correcting/editing student work. A couple of homeschooling moms and I touched on this last week in a conversation about dissecting for biology. She loves doing it and suggested that we send our kids to her house to dissect when needed. Then she mentioned how difficult it is for her to grade her 12th grade son’s English papers and asked if one of us could do that in trade for the dissecting lessons.
If you could find someone–a friend or relative, or another homeschooling parent–who is skilled enough at writing to do this for you, that would be one suggestion. Or, you could try to find a college student majoring in English who might correct your child’s work, maybe in exchange for doing laundry or a home-cooked meal if you can’t afford to pay them to do so.