I I had been trying to find this story for ages but cant find it.
so your help will be really appreciated.
This is the harry potter captured and tortured by death eaters along with Snape fanfic.
There Harry and Snape developed some bond (not slash!) and began to respect each other.
I think the whole story in that fanfic revolve around their torture plot. And, I think one of the death eater used some cursed knives on harry that will never heal and will reopen from even a scratch. In the end they were able escape but Peter Petigrew casted the killing curse on Harry and Snape thinking Harry died took his body to Hogwarts. But somehow Harry had survived the curse and his horcrux was destroyed.
Their was also a sequel in which harry glamoured as Snape's Nephew or son lived in hogwarts and was mistreated by Ron. Their were also some other sequels of this story.