When I look upon the ground
And I see your shining heart
I know it doesn't belong
But I can't help but pick it up
I'm scared of what the outcome
Will do to unravel the stitches
Holding together the pieces of your
Beautiful, beautiful heart
Like I said before
Your heart doesn't belong here
It's to squeaky clean
To enter someone like me
We both are lost and
Have not been found
And I guess that's why
Our strength is doubled
When we're together
If you want that, and nothing else
I'll gladly give it to you
But you come so cute and sweet
I can't stand to stain the pieces
Of your beautiful, beautiful heart
You're so fragile, and
Experience should tell you that
I'm not the guy you should be with
Maybe someone else would do
But why won't you just walk away
And leave me to my dreary days?
I've earned them, as you can see,
And yet you still stand with me
You're an angel, I'm sure of it
But you're broken, and I can't heal this
So why don't you find a worthy man
Or even go back to your perfect Heaven?
I love you dearly,
I wish we'd never part
But I won't shatter the pieces
Of your beautiful, beautiful heart
Rather than try to write from a generic guy's point of view, try writing from a specific guy's point of view. Each guy is different, just as each girl is different, and just as some girls are more masculine than feminine, so too are some guys more feminine than masculine. Gender isn't a something that's set in stone, and barring stereotypes, there's really now way to say for sure that something or someone is or isn't masculine/feminine.
Instead, if you're going to write from a guy's point of view, write from the point of view of a specific person. He happens to be a guy. Okay. How does he view the world? Is he the poetic type to begin with? He's probably not going to conform to stereotypical male behavior if he is, and he'll come across as being more "feminine" as a matter of course. What are his particular interests and quirks? Try and incorporate those into the narration and imagery.
Basically, create a living, breathing character whose distinct voice you can capture in a poem. If you manage to do so, then it won't matter what gender the character is "supposed" to be; it will show through naturally.
That said, if I hadn't read the author's note at the top saying that this poem was supposed to be written from a guy's point of view, I wouldn't have known until the sixth stanza. Honestly, it could go either way, not because of anything in particular you did, but more of what you didn't do. The entire poem is rather generic in language, and since it's so generic, either gender could have said all the above.
So, first things first, get a character with a distinct voice you can convey. Secondly, convey that unique voice by not relying on generic language.