Please help? I'm looking for anything (fiction или nonfiction) that fouces on a gay couple in either a time или place where it's unacceptable.

There a little unecceptable gayness in the City of Кости Trilogy. OH! and iin pretty little liars series except its with Лесбиянки instead.

The Остаться в живых language of cranes by Leavitt David will be good - it's about a group of gay friends.
Affinity by Sarah Waters has some lesbian background.
Ты can also try
A Single Man by Christopher Isherwood (about a gay man whose lover died)
There's also Ai no kusabi by Rieko Yoshihara, gay sf, but there are many "hard" scenes, so be warned.
Sputnik Sweetheart by Haruki Murakami focuses on lesbian couple.
There's also the famous Brokeback Mountain, short story by Annie Proulx.

Hope it helped.