The problem with rocking short hair is that it makes you look younger (compared to how he could look with longer hair). And in TeamXlink's case, that's not a really viable option.
I've rocked long hair for a few years (though admittedly at the time I didn't do a proper job), then cut it down and currently re-growing, because longer hair, well taken care off is a big advantage.
For good examples of longer hair without beard/stubble google:
"tom cruise in rock of ages"
or "Christian Bale" (looks great with both facial and without)
or
http://www.fashionbeans.com/2013/intermede/
Whatever you choose make sure to raise the hair at the front so it doesn't cover your forehead (as it does now).
Naturally, the "bieber" look should be avoided at all costs unless you're in a boy band, and if that's the case, hair is the least of your problems
But Natty raises a good point,
Until nature takes over and you'll develop more masculine features, it is something that should be addressed.
Working out would be a good idea, but until you get noticeable results consider wearing clothing that adds volume to your shoulder area (buttoned shirt+fitted blazer would look good on you, just make sure the fit is spot on).
On a side note, boots are also awesome for adding a masculine edge to your overall look.