Fortunately for you, there is no good argument that homosexuality is wrong. But honestly, it does take a certain nontrivial amount of understanding to realize that- an understanding of things like: the list of the most common informal logical fallacies (or... all of them, because why not, and once you learn them, you see them everywhere). And those aren't someething that is typically taught in school (I had to pursue them on my own time).

(A while back I found a personal webpage that systematically shot down every single homophobic argument using reason and those fallacies... and I haven't been able to find it since, unfortunately.)

So, among many other injustices that might be rectified (or at least ameliorated) by a broader understanding of fallacious arguments, homophobia would definitely be one of them.

(Also, personal note, I'm sorry about any injustice you've had to endure because of your orientation and others' lack of understanding.)