One great fanfic where Sam collapses is 'The Unseen Burden' on FanFiction.net. It's a well - written piece that delves deep into Sam's character and the reasons behind his collapse. The author does a great job of building up the tension before the collapse and then handling the aftermath in a very realistic way.
A lesser - known but really good one is 'When Sam Falls'. In this fanfic, Sam's collapse is part of a larger mystery that the other characters, especially Dean, have to solve. It has a great blend of action, mystery and emotional moments related to Sam's condition. The description of Sam's collapse is very vivid and makes the reader feel the urgency of the situation.
I'm not sure of a specific one off the top of my head. But you can try searching on fanfiction websites like Archive of Our Own. Just type in 'Supernatural Sam strangled' in the search bar and you should get relevant results.
Most fanfictions in the 'Supernatural' fandom focus on their adventures, their relationship in a positive light, and their growth. A plot where Dean hits Sam is quite against the essence of their relationship. But if there are any such fictions out there, they would be in the darker corners of the fanfiction world. It's important to note that this goes against the love and respect they have for each other in the show. So, I would rather suggest looking for fictions that celebrate their brotherhood.
One popular 'Supernatural' fanfiction with this theme is 'The Unintentional Wound'. In it, Dean's actions during a hunt have unforeseen consequences that end up hurting Sam, both physically and emotionally. It delves deep into their complex relationship and how they deal with the aftermath.
There's also 'Sam's Struggle'. In this fanfiction, the abuse Sam has endured shapes his relationships with Dean and other characters. It's not just about the abuse itself but how it affects his decisions, his self - worth, and his ability to trust. The writer does a great job of exploring Sam's psyche in the context of the Supernatural universe.
One great 'dean sam supernatural fanfiction' is 'The Road So Far'. It delves deep into the relationship between Dean and Sam, exploring their adventures in a new light. It has some really cool plot twists and stays true to the characters' personalities.
Some fanfiction worth checking out are 'Sam and Dean: The Lost Years'. It fills in the gaps of what might have happened during the times not shown in the series. 'Dean's Choice' is a story that shows Dean making some tough decisions that change their lives. There's also 'Sam and Dean's Greatest Hunt' which is full of mystery and excitement, with the brothers facing a powerful and elusive foe.
I really like 'Young Sam's Discovery'. This fanfiction takes us through Sam's discovery of his own powers. It shows his confusion, his attempts to understand what's happening to him, and how it changes his perspective on the world around him.
There's also 'Solo Sam's Supernatural Journeys'. In this fanfiction, Sam's solo adventures are depicted in a very interesting way. It shows how he uses his intelligence and skills differently when he's alone, and the author has created some really unique supernatural creatures for him to face.
There's also 'Sam's Hidden Love'. This fanfiction delves deep into Sam's inner thoughts and feelings in a gay relationship context. It's a bit more emotional and really gets into the psychological aspects of the character. The author does a wonderful job of creating a believable and engaging story around Sam's love life.
Well, 'Sam and Sarah: A Supernatural Alliance' is worth checking out. It starts with an unexpected encounter between Sam and Sarah and then unfolds into a story full of mystery, with them trying to uncover the truth behind a series of strange events while also dealing with their growing relationship.