I'm 5'2", 115 lbs and have a similar build as you, so I can relate to what you're going through when it comes to finding guy clothes that fit and look good. I also am unable to pass, but on some days, I'm able to look gender ambiguous. With that, I've been able to build a decent wardrobe that not only passes for male, but looks flattering and kicks ass!

For me, finding pants has been my toughest challenge because of that fact I'm bottom heavy. I've got heavy thighs, wide hips and a big butt, even though I get plenty of exercise. Pilates moves helps in reducing the size of the hip, thigh and rear area, but I'm still heavy down there. With that, I was able to find a great guy wardrobe that fits and looks great on me! For pants, I wear short women's pants from places like Eddie Bauer and Kohls. I choose only the pants that look like they can pass for male, and both places have pants that are available in short (petite) lengths. Since you're only 5 ft though, the short/petite sizes may be a little long, so you may end up taking them to a tailor, but at least they will fit you around the hips, rear and thighs. Women's short Levi's pants are also good, because they look like men's pants, however, their sizes run SMALL, so they may be too tight. Right now, my favorite pants are from Kohl's and I highly recommend them. I am in love with these pants!!! The side pockets and zippers they have along the leg and knee area are great in that they add a masculine touch and gives a slimming affect. Those extra pockets is what gives these pants the slimming affect, in that it will draw the attention away from your hip and thigh area. These are available in short, average, and tall lengths and are in 4 different colors. Here is a link for the cargo pants .... "Sonoma life + style Slim Straight-Leg Cargo Pants - Women's"
http://www.kohls.com/product/prd-1896714/sonoma-life-style-slim-straight-leg-cargo-pants-womens.jsp?skuId=95859150Ignore that they're women's pants because no one will ever guess that they are. That's how masculine they look! I wear mine with women's combat boots. I look like I could kick some serious ass in these pants with those black army style boots of mine.

As for shirts, I found some great looking button down shirts from places like J Crew, Macy's, Lands End and LLBean. All of my shirts and sweater are in big boy's sizes. I wear a size 14 and 16 in for boy's shirts and sweaters. I hope this helps.

Miles