There are often fanfictions that pair him with other characters from the shows or movies he has been in. Some might create a romantic storyline between his character and another, like a forbidden love story within the context of the fictional world they inhabit.
You can start by searching on popular fanfiction websites like Archive of Our Own (AO3). Just type in 'Dominic Sherwood' in the search bar, and it will show you a list of relevant fanfictions. You can then sort them by popularity, kudos, or bookmarks to find the ones that are likely to be good.
I don't have enough information to determine exactly who Dominic is. He could be the protagonist of the story, a person with a special connection to the war dance.
I'm not sure exactly who Dominic is without more context from the story. But he's likely a person who is the focus of this 'my 600 pound life' story, probably someone who has a weight - related struggle.
Sherwood is purely fictional. It takes creative liberties to weave an engaging tale, rather than being rooted in reality. So, don't expect it to be a true account of events.
The real story of Sherwood is likely to be about the Sherwood Forest in England. It is famous for being the legendary haunt of Robin Hood and his band of Merry Men. They were said to live in the forest, robbing from the rich and giving to the poor.
I don't think it's a true story. 'A Haunting in Sherwood' is probably just a creative concoction to thrill and entertain, rather than being based on actual events.