He has a 10 year GC, there's nothing you can do to have it taken away or send him home. The only way the I864 will be enforced is if he becomes a public charge, which I don't see happening with a young man his age. You can't report him for fraud, you sent in a lot of evidence to prove the contrary. You CAN report his employer for paying him under the table, neither of them are paying taxes on his income and that's illegal.
If I were you I would get as far away from him as humanly possible, make sure you and your baby are safe, file for divorce and never look back.
You can do this, you're a strong, intelligent woman, you have a lot going for you. I wish you the best. Have a safe delivery and congratulations on your little bundle of joy. Please keep us updated.