@AIJoy, I am so sorry about your situation with your rooster.
Our rooster was behaving badly toward our hens also, especially the hen at the bottom of the pecking order. He would always yank their feathers out and it got to the point when our bottom hen would not even come down from the coop because of him. There was really no explanation for his behavior; sometimes roosters are just rough. It made us so sad to see our hens so nervous all the time. The only time our roo would leave them alone was when we kept him occupied with treats and entertainment; but we obviously couldn't be there all the time to keep the peace. We ended up re-homing him because it was just getting to be too much; the hens would have to come first. Our hens are a lot happier now.
Maybe try re-introducing your rooster and hen, keeping them both occupied with treats while he warms up to her little by little. I think what you have been doing (keeping them separate then supervising them together) is a good idea; and if you are set on keeping both rooster and hen, keep doing what you are doing and it might work out.
I sincerely apologize for the bad experience you have had on BYC, I hope you will give the helpful people here another chance.
Good luck!