I've always thought that you should sleep in the same room with your new kitty--something about snoozing together (such a safe and pleasant activity) will help bond the two of you. When my ex-feral boy, Bill, came to live with us, I slept with him in the spare bedroom for his first two weeks. The first night, he hid under the bed and only came out for food, water and sandbox. The second night and all subsequent nights he spent on the bed with me, usually pouncing the covers whenever I moved. He's very confident now.

Secondly, be very patient and gentle. Speak softly, move slowly.

Thirdly, get an interactive toy, like a feather on a stick, and play play play with him. He'll associate you with lots of fun and be more confident with you.

Yes, I agree that food should be offered by you, personally, not left out all the time. Make it a reward for coming closer to you.

And finally, thanks for being willing to do this for this frightened little kitty--you are storing up treasure in heaven!