hey
I would seriously take the turtle to a vet to get that wound checked, because wounds can lead to infection. And we dont want that.
Is the turtle moving around alot, or just sitting there!
I currently feed my turtle some turtle pellets which can be bought at your LFS, but because its a wild, it probably A wont eat it Or B will take a while to start to get used to humans, and feel safe to eat, Mine took over 3 weeks to start eating when i was in the room, Also i have noticed that some guppies start to disappear, lol
Anyway
Cheers Nick