I had a friend a long time ago take in a feral cat. It was severely abused as it had burns and showed signs of physical abuse as well as being very malnourished. As the cat recovered, it was extremely timid and became defensive whenever someone tried to pet it or go near it. Over time, however, she became more relaxed and less afraid of people. Eventually, she became very friendly towards people she knew and would let you pet her all day.
A family member of mine has had his cat for 15 years now and he is the only one that it likes. If anyone besides him tries to pet it, or (god forbid) pick it up, it will become violent, clawing and biting. I recently stayed at his house for about 3 weeks and by time I left, the cat would occasionally approach me and lay next to me. A few times it would let me pet it but it was obvious that it wasn’t a fan. He would even bite or claw his owner every so often when he was being pet. It isn’t a mean cat, it just doesn’t like to be touched or pet. Just like people, animals are all different.
While these cases aren’t exactly the same as yours, I think shows that it just takes time. Some cats may never enjoy being pet, and this might be the case for yours. However, it might still be possible to form a bond. The family member I talked about loves his cat even though it will occasionally scratch him. They get up every morning at the same time and it sits next to him in his living room each morning as he drinks his coffee.
Please don’t consider yourself a monster. From your post, it seems obvious that you care and don’t wish to cause harm. I’d give it time and try not to be too forceful. If it seems like he doesn’t want to be pet, or runs away, give him space to chill. Unneutered male cats can sometimes show aggressive behavior. Maybe your vet could advise whether or not neutering him would help.
Ps. Hope your job interview went well!