So sorry this happened. Years ago I had a feral in the house that I kept in a spare bedroom, I could not go into the room without being attacked, still have my scars from him. I could only open the door enough to slide in the food and water and I kept the litter right by the door so I could quickly pull it out to clean and quickly shove back in. It took about a month before I could enter the room without being attacked, he would eventually eat with me in the room, growling all the while he was eating. After a few months all of a sudden one day he started winding around my legs purring like crazy, it was as if a little switch was flipped and all of a sudden I was his best friend, had him for 18 years. Point being, patience, patience and more patience will win the battle.