I understand the challenges of working around your work schedule and all that - but if your goal is to bulk and you aren't - that means u arent' eating for it. Esp w/ var. Altho to my example above - my weight doesn't change much but my body composition does - it might help to get an accurate BF reading every week so you can tell for sure. But you still arent' eating enough. And the fact that you aren't hungry is telling me your body is probably adapted to the fuel it gets --- try upping your food a bit and see how it goes. Regardless of the var, w/ an increase in cals you should be able to build up some really nice strength just w/ that. I'll point u to both Treilin & sbt's logs on this board for evidence of that.
I'm a desk jockey as well - have been for 20 yrs - 10yrs as a software engineer, 10 as a product mgr for software companies. I've spent an avg of easily 15 hrs / day in at a desk for 20 yrs. I still need to eat more if I want to build muscle mass. If you arent' eating enough to support the activity you are doing, you might even be catabolizing your muscle to support that.
I'd suggest upping your cals to around 2000 for a week and just see how you feel. I'd keep the ratios around 40/30/30 -- increase a little each day if you need to just so you don't feel stuffed -- but if your point is to bulk, then bulk. It didnt' sound like you are going to compete - but if you were, then you'll find that it really doesn't matter how comfortable u are w/ your body day to day (meaning if u are bulking & u feel stuffed & fat, tough shit - you're bulking... you'll be cutting at cuttign time and your goal is to have a certain look on stage on show day, not to feel comfortable each day up until then - because then you probably won't hit your goal of tight on show day -- the two goals conflict.)
But honestly I'd just say try it and see what happens. If you dont like your results now -its obviously due to your diet so IMO time to change the diet.