https://www.mangago.zone/read-manga/otouto_no_otto/
https://www.mangago.zone/read-manga/shimanami_tasogare/
https://www.mangago.zone/read-manga/welcome_to_room_305/ this one is from 2008, so keep that in mind, but even then i'd say it's ahead of its time in many ways. first 20 chs or so might seem repetitive but keep going. very touching character interactions including family/sibling dynamics, deals with homophobia and transphobia.
So this is not exactly what you’re looking for because it’s not about being gay,it’s about being asexual, but it does touch on some things you mention, so it may still be an interesting read for you.
https://www.mangago.zone/read-manga/kimi_no_sekai_ni_koi_wanai/
Love strongly surprise
Hey I need some slice of life, or anything actually, that’s similar to “I think our son is gay” or “mom, I’m gay.”
I really need some stories that talk about what it’s like to be a closeted gay facing society’s harsh standards and expectations to make myself feel better. Any recommendations?