Mental issues + gay male relationships + 18th/19th/20th century

I've just finished The Bell Jar by Sylvia Plath and I'm going to read EM Forster's Maurice. I think i might enjoy something between them, too. Like: setting as in Maurice but with no happy-end and with mental troubles, anxiety and stuff. I would also prefer it would be classical or "semi-classical" literature, too: no [...]