The letter:
[Insert Agent Here]
Normally, I would recommend leaving word count, comparison titles, and so on to the end of the query. A little personalization up front (I'm querying you because we met at ALA last year, or I'm querying you because I love that you represent Author X) can be great, but isn't always necessary. In the long run, the one and only thing that is going to sell an agent on representing you, is your story. I say get right to what matters.
So let's do that, and jump into the important part, the meat of the story.
...
First of all, let me just say before I even get to the content, I don't like what I see at first glance. This is a large chunk of text, not broken up into separate paragraphs at all. Traditionally, query letters are about 250 words (for the story part), broken up into three paragraphs. There's nothing wrong with breaking the "rules," but if you're going to do it, do it in a way that improves your chances.
Additionally, the paragraph below (before I touch it) is 182 words. That's not so short that I would say you should definitely increase it, but the problem here is that shoving it all into a single paragraph actually makes it look longer than it is.
Anyway ...
17-year-old Adam Sutton knows he should have kissed his boyfriend, Terry Connelly, by now just as he knows it is strange and yet intriguing his best friend, Evan Michaels, kissed him Kissed who? Watch your pronouns here. I'm not sure if Evan kissed Adam or Terry from this sentence. in the front seat of Evan’s Tahoe. This is a nice detail. This is the kind of thing I like to see in queries: specificity. We don't necessarily know for sure just from this one word, but this indicates a lot to me. If a high school kid has his own car, and it's something as nice as a Tahoe, they probably come from a relatively wealthy suburban area. Specific details like this go such a long way in a query. While exploring his newly-disrupted world, What does this mean? It's basically both vague and redundant. "Exploring" is vague, because we really have no idea what that means, and "newly-disrupted world" is redundant, because you just showed us the world was disrupted. Sometimes a little reminder is a good thing, but don't combine it with vague language. Adam receives disturbing news of a trauma that
Okay, so in summary: content-wise, you've actually got a strong premise here. I think the market (I'm no expert, but still) is looking for diverse stories like these, and I think that sets you up for success from the get go.
Structure-wise, this query needs some work. I would recommend re-writing to try to match something closer to this format:
"Seventeen-year-old [One or two words describing him as a character, for example: drama club president, or: shy but friendly trumpet player] Adam Sutton knows he should have kissed his boyfriend Terry by now, but he's been a little freaked out ever since his previously assumed to be straight best friend Evan kissed him in the front seat of his Tahoe.
Still reeling in the emotional whirlwind aftermath of that night, Adam's world gets a little more confusing and a lot more dangerous when [describe the hate crime] at their stiff-upper-lip boarding school, Pisgah Heights Academy." ... Go on to talk about Carter, the GSA, the protection they offer, and then ...
In a final paragraph, focus on the choice Adam has to make of whether or not to confront Carter. I would probably recommend you bring up the locked door, and the secret surrounding it, in this paragraph as well. Ending the query on the note of whether Adam should keep Carter's secret, and protect the victim, or out him, and side with the truth, will leave the reader itching to read the pages, which is exactly what you want to do.
I hope that makes sense. I think you're off to a really good start here, and you just need to rework the form and style of how you have all this information laid out. Let me know if you have any questions.
That's it.
What do you all think? Hopefully you can make sense of my critique, with all that blue in the post. Would you recommend any other changes?