The huge advantage of homeschooling is that you can let your DC follow their own interests and that you don't have loads of time taken up by dealing with all the other kids.
Also, don't forget school is about socialising also, it's important.
What's your DS interested in? My son loves drawing and computers so I've let him develop this, and he's teaching himself new art-related software from YouTube, 'we're calling it his "personal project". He's spending at least half his time on this and his other interests and has made huge progress, I'm really impressed with what he's putting out. The stuff he's doing with the 3D software he's using for example, I couldn't do.
I'm also letting him spend regular time on games where he can talk to his friends (like fortnight) as this interaction with his mates is so important to him. (He does need to have done sufficient work before I'll let him).
He's doing the maths stuff the school set, mostly, but we're picking and choosing what we want from the other stuff. I tried to force him to do the English but he really hates it and after he showed me a lesson I can understand why! Talk about stripping the joy out of learning. He reads at a higher level than expected for his age anyway, so instead I've said he can read books with a notebook and note down words he doesn't know as he goes then look them up.
Plus he's writing a blog about his "personal project" (which he hates doing as hates writing at all, but I do insist on this, it's the least bad of the writing options we could come up with).
I had a call with his teacher last week and was honest about what we're doing. She said as long as he's being productive, she's happy.
Sorry for the mammoth post, but what I'm trying to say is, give him and yourself a break. Can you forget about some of the schoolwork and give him stuff tailored to his interests instead?
Schools don't give all the DC the same work as it's the best for them educationally. They do it because each teacher has 30 DC to teach AT ONCE! (My mind still boggles how they manage to do that!)
But, you don't have 30 DC to teach, so why not play to the strengths of the set up? If you let your DS follow his interests, he'll likely be more engaged.