Hi Natalie, sorry I dont have an answer to your problem, but hope its not the same as mine-- my cat has run away 25 times since we moved in January this year-- I too lived five minutes walk away, and he goes back to his old haunts--he is so distressed each time I try to find him, that I have tu wait until he is starving before he will come anywhere near me, then I try to lure him with chicken-- after 9 months, its getting really distressing..
thankfully he doesnt have the injuries that your cat has, which would be a nightmare.
Nobody seems to know what to do-- I darent re-home him(if I could catch him) as he might run from thereto an unknown destination.
Im terribly afraid he will starve to death rather than come home--
I hope your problem will ease soon- he may just get used to his new home-- if you find any answer, I would be very grateful to know of it,
thank you,
Chris