Wish I had some super advice for you re: how to reach queer youth with your novel. Of course publication is the key and then gaining a reading audience.
My best suggestion is to find other books that are similar and appeal to gay teens. The publishers that have taken on those books would be more open to accepting subs from you.
You might get in touch with other writers who are writing for the gay reader and see if they will share names of agents who have taken them on. Malinda Lo is a good example.
I wish you a lot of luck with your story.
I'd like to add that getting involved in an organization like SCBWI (The Society of Children's Book Writers and Illustrators) offers a lot of information on the craft and business of writing for teens, as well as opportunities to get your work in front of agents and editors.
I've been involved with SCBWI for more than 6 years now, and am honored to be part of the team that blogs their international conferences - you can find out more about those conferences at our official conference blog here.
The organization has many smaller local events (like schmoozes - and yes, I co-coordinate one of those, too - out in Los Angeles) and is a wonderful resource.
As far as getting queer youth to know about you and your writing, that's where marketing and social media like facebook and twitter can play a role... but first, writing the book and making it the best it can be is key.
Best of luck on your journey, and giant thanks to C. Lee for sharing her expertise!