Then your poem should stand as it is. You say it's more a narrative, and it is. But the thing is, what about the story could be described in greater detail? It's definitely possible to keep intact the basics of your poem currently, while adding or omitting certain extras. For one thing, the reason you repeat the first two lines at the end, certainly makes the ideas of invisibility and impossibility the two central themes of the poem. You could run with that and describe in what ways your invisibility reflects upon the impossibility, and vice-versa.
For now, the poem simply stands as a description of what happens, because you are invisible to the object of your affection, and the denial of your unrequited feelings. You cry, and you stand alone, while the object looks the other way. Even with this, you could have a better go at further detail. All I can really say to help is to apply more imagery.
I mean, you don't have to take my advice. But you could simply do this: read each line, and think to yourself, how could you describe that line more. Like, the first line: "To you, I am invisible." Invisible in what way? Are you like a ghost, wandering down the hallways? Are you so small to his view, that you are naturally unseen? And because of this invisibility, you can move further with that. Because you do remain unseen, what chance at requite remains impossible. How impossible is impossible? So impossible, that all the countless, worthy tears that you weep could not fill the void of emptiness within your heart? So impossible, that your dreams carry on incessantly, but you would rather bask in the night than risk a broken heart during the day? It's all a matter of magnitude, I think, when it comes to your poem.
But, it looks good the way it is. Often, it's hard to really look at one's own poem and really tell if it needs work. It's all up to you, Kelly.
"I like refried beans. That's why I want to try fried beans, because maybe they're just as good, and we're just wasting time." - Mitch Hedberg (1968-2005)
"Football is about if you want to run and fight for each other, if you really want to play that killer ball." - Robin van Persie, Arsenal FC