It sounds like you are doing everything right. A weight loss of almost a pound a week is actually not bad. I know it is frustrating because with all your hard work, you'd expect more weight to come off in that time. However, what is likely happening is you are losing fat but building up muscle at the same time. Muscle is more dense than fat and weighs more. So it looks like nothing is happening, but in reality you are becoming healthier. Other ways to assess your progress is to measure inches and body fat percent. The weight on the scale may not be changing much, but the inches and percent body fat could be decreasing. Also building up of muscles doing the circuit is good because not only do you get toned and look better, muscles also burn up more calories so fat loss is improved.

Continue with what you are doing and don't lose motivation. A slow weight loss is usually the best, as you are learning healthier habits over time and will be less likely to gain back the weight once you reach your goal. Hope this helps.