As everyone has said - it seems possible, yes, but difficult. You will need to stick to your plan like glue, and persist even through the weeks when you don't see as much loss.
You're starting out almost exactly where I did - I'm 1/2 inch taller and was ~10 lbs heavier (and 12 years older). I have lost 37 pounds in 12 weeks by calorie counting (1200-1500/day) and exercising 5 days/week beginning at week 4 (3 days cardio, 2 days weights). That's an average loss of ~3 lbs per week, but the weekly drops at the beginning were larger than they are now and the rate of loss will undoubtedly slow as I lose more. My plan is completely manageable, though, as well as safe according to my nutritionist, and I don't have trouble sticking to it.
I would add more exercise to your plan when you can manage it (though I think 4 days/week is a good place to start), and watch your calories strictly. Weighing your food rather than measuring will help you keep your calories within your target range (I don't do this now, but will at some point).
Good luck!
