Well, there are several fanfic communities out there. Some Tumblr blogs are dedicated to sharing and discussing Harry Potter fanfics. You could try searching for tags like #SnapeHarry #AbusedHarryFanfic on Tumblr. There might be users who have either written or know where to find such a fanfic. Also, Reddit has some Harry Potter fanfic subreddits where you might be able to find it if you post a request or search through the existing posts.
You can also check out some independent fanfic websites. However, be careful as not all of them are reliable in terms of quality or legality. Some might have a smaller collection but could still potentially have the 'Snape finds abused Harry' fanfic. You could start by doing a general Google search with the exact phrase 'Snape finds abused Harry fanfic' and see what websites come up. But always make sure to avoid any sites that seem sketchy or ask for too much personal information.
One place to look could be Archive of Our Own (AO3). It has a vast collection of fanfics, and you can search for ones with this specific plot. Just use the search bar and type in relevant keywords like 'Snape finds abused Harry'. Another option is Fanfiction.net, though the tagging system there might require a bit more digging to find exactly what you want.
In such a fanfic, Snape might initially be shocked. Given his complex relationship with Harry in the original series, he could struggle between his old grudges and his sense of duty. He might take it upon himself to protect Harry secretly at first, perhaps by using his position at Hogwarts to keep an eye on Harry's abusers. For example, if it's the Dursleys abusing Harry, Snape could find ways to make sure they don't go too far without revealing his true intentions.
In the fanfic, Snape's reaction could be multi - faceted. He might start by investigating the abuse more deeply. He could use his skills as a Potions master and a former Death Eater to find out who is behind the abuse. And then, he might take steps to ensure Harry's safety. This could involve enlisting the help of other teachers or even trying to get Dumbledore more involved. He may also start to teach Harry some extra skills or give him potions to help him deal with the emotional and physical trauma of the abuse.
Snape's reaction could be quite mixed. On one hand, he might be angry at Dumbledore for not doing more if he knew about the abuse. He may also feel a strange sort of empathy towards Harry. After all, Snape himself had a difficult childhood. So, he could start to be a bit more lenient with Harry in his classes and try to subtly offer support.
After Snape discovers the abuse, the relationship undergoes a major transformation. Snape begins to protect Harry from not only the Dursleys but also from any potential threats at Hogwarts. Harry, who has been starved for positive adult attention, starts to trust Snape. Snape, in his own brooding and complex way, starts to care for Harry's well - being. He might even start to teach Harry some advanced magic that he wouldn't have taught him before, seeing Harry's need for strength and self - defense in the context of his abusive home life. This new relationship dynamic is a far cry from their initial animosity.
Harry might start to receive more protection at Hogwarts. Snape could put in place some measures to keep him safe from further harm. For example, he might assign some students to keep an eye on Harry when he's in vulnerable situations.
In the fanfic 'Malfoy's Revelation', Malfoy is paired with Harry for a project. As they spend time together, Malfoy notices some strange behaviors from Harry, like flinching at sudden movements. After some snooping around, he discovers that Harry has been abused. This new knowledge makes Malfoy more empathetic towards Harry and he tries to help him in his own way, which includes standing up for Harry against some of their mutual enemies at Hogwarts.
In fanfic, Snape can definitely care for an abused Harry. Some fanfic stories might rewrite Snape's character motivation. For example, his long - standing grudge against Harry's father might be set aside as he realizes that Harry is an innocent victim of circumstances. He could then use his skills and knowledge to help Harry deal with the abuse, whether it's emotional or physical. This could be a way for the writer to explore themes of redemption and second chances for Snape as well as providing a different kind of support system for Harry.
Often, Snape is shown as a secret protector. He might use his position in Hogwarts to keep Harry away from those who would harm him further. For example, he could give Harry extra potions to help him heal from physical abuse or offer advice on how to deal with bullies.
Snape's reaction could be multi - faceted. He might be angry at those who are abusing Draco, but also a bit conflicted because of Draco's family's ties to the Dark side. He could use his position as a teacher to give Draco some extra guidance and support, perhaps in the form of private tutoring sessions where he can also check on Draco's well - being more closely. He may also start to question his own views on the Malfoy family in general.
Snape might be secretly pleased at first, seeing as he has no love for Sirius. But then, being a teacher, he'd probably feel obliged to report it. He also might use this situation to his advantage against Sirius in the wizarding politics within Hogwarts.