Repressed gay works just fine tbh, most people probably use “closeted” but that’s more colloquial.
However, referring to a gay person as a “gay” can be a bit problematic as it strips their personhood from the statement. A lot of bigots will refer to gay people that way to imply they are lesser. I dunno if that’s how it works in other languages, but at least in English it’s generally more respectful to refer to groups as people specifically. So you’d always say “gay people” or “black people” and etc.
That’s a fair point, actually, repressed probably is more accurate for what your saying