Awww...you are a very special person for taking the lil guy in
I too raised a feral kitten male I think he was like 5 to 6 weeks old when I found him...Took both my sons over an hour to catch the lil fart lol...but they did...I ended up keep him couldn't part with him, Rex went to rainbow bridge 2 years ago of old age, he was 16 years old(god bless him)
What I did was... when I fed him I would touch him as much as he would allow me to...than once he got use to that I would hold and play with him ALOT with some string and an old piece of paper balled up they love that and than I started letting my kids play with him...within 2 weeks he was littered trained...sleeping and purring up a Strom with us
...he was the best lil kitty ever...just spend LOTS of time with him, he will come around...I hope that helps..Good luck!!