It sounds to me like you're having the problem because you're defining the character based solely on his sexuality.
Let me explain my process. It seems different from what people expect.
I'm not defining the character yet. I'm defining the problem, which will help define the character.
Take, for example, the problem of "unfamiliar with the city". A person unfamiliar with the city has certain qualities: he's not from the city, lives far enough from the city that travel there is inconvenient, and doesn't travel enough to overcome the inconvenience. You can't make someone who was raised in downtown Chicago "unfamiliar with the city". If you put him in a Chicago suburb, you can't give him a car, and that opens up a whole new set of problems. So the problem, which is important to the plot of the story, drives the definition of the character. And once you identify where your character is from - say, Roosevelt, Utah (population under 5,000) - you know other things about the character. You know what jobs he's likely to have had, and what sort of people he normally sees, and what religion he probably is, and all of that has had an impact on his life.
I know, from the problem "seeking but not finding love in the gay community", that this character is a gay man. That's all I know. This much is required by the problem as I understand it. But since my understanding is incomplete, I could proceed to flesh out the character with qualities that - in an actual gay man - would make it
trivial to find love in the gay community. That character is every bit as inauthentic as the Chicago native who is unfamiliar with the city. He needs to be in an
emotional Roosevelt, Utah.
You can't apply the "gay" label as an afterthought. Those who do simply don't get it: being gay
pervades your existence. It affects you long before you know it's what has been affecting you. It's so integral and essential to your life, that life
has no meaning and
can't be understood without it. You might just as well define two characters the same way you normally do - Joe went to Harvard Medical and is a pediatrician, while Bob went to MIT and is a particle physicist - and then say "oh yeah, they're also conjoined twins". It simply doesn't work.
You might get away with a character defined as though he were straight, who has
just realised he's gay - but that's the only time you can realistically do this, and all the same, that realisation is inevitably the key to a puzzle that everyone around him has seen. Being gay may be new
knowledge, but he was
always gay.
EDIT: neglected to address this bit.
In that case, make his flaw reflect something about the protag and the protag's journey.
That journey is from homophobia to understanding. That's why there have to be all these gay people.