I'm certain that the problem lies with my diet, but not with the quality of the foods/macro ratios--simply put, I'm just not eating enough. As I said, I'm low-carb during the week so I usually get around 200 grams of protein from chicken/beef, 120-130 grams of fat from cheese/nuts/fish oil, and trace carbs. Calories are typically around 2200.
Let me assure you, I've been lurking around in these forums long enough to have read about all sorts of diets/training programs--I really started this topic to see if anyone shared a similar experience/situation. What I've taken so far is that I need to abandon the low calories, add in some carbs around my workout, and keep a close eye on the mirror for any fat gain.