Hi kris & welcome to EF! Buns pretty much nailed it - its the diet. You know that old saying, "You are what you eat'... its true! If you eat random shitty food whenever, your body has to filter thru a lot of excess sludge to get to the nutrients it needs, it never knows when it is going to get the next meal and then you ask it to lift 5x/week and do an hour of cardio / day. There are lots of degrees of strictness & speed of progress depending on how diligent and consistent you are in your program - so if you want a cheat meal a couple times / week or you can't get in the food prep time or whatever limitation, then you have to expect a slower progress rate, but you will still get progress. But just as you've put in the time for consistent lifting & cardio, you need to go the extra mile and be consistent in your eating as well. I guarantee you will see quick results!
RE: your stats - if it helps at all I'm 5'7" and consistently my body settles in between 162 - 165 lb. My bodyfat is probably around 16-17% but I also consistently wear a size 4-6 pants and the last thing anyone would call me is "fat". I'd enjoy being leaner, but for the stats I've got I wear it pretty well.
If you've stayed pretty consistently at 15% I'd guess your body has adapted to that point given the consistent training regimen and inconsistent diet. So this is what your body now considers "normal" and this is the best response it can give you. The fact that your bf hasn't changed means you need to change something to spur some progress. Diet will be a very easy thing to change. May take a day or two to figure out the best way to prepare & pack your food choices for the next day - but every one of us has been under duress and figured it out. I've been carrying food for a whole day (I'm completely self-contained and ready to accommodate any change in my schedule from 6 am until the next day if I have to because I have everythign with me & ready to go) for more than 6 yrs straight. This is with leaving home for 5 am cardio and coming back after 10 pm after a full days' work, commute, gym and home again. Just takes a little planning & organization to see what works best for you. But once you figure it out, you are golden. YOu'll probably save some money on buying the take out food too.
15% is absolutely not a bad bodyfat - what is your goal? Drop bodyfat? Lean out? More muscle? Get rid of fat in a certain area? More strength? What?