You would probably lose more weight if you stuck to the 1200 and cut the exercise out entirely or kept it to a 20 minute walk a few times a week (or daily).
Overdoing the exercise on a low calorie diet won't really help with a short term weight loss and it won't show on the scales even though you are burning fat:
1. You will be changing your body composition from being fatty to being muscly - which is a great thing and will change your body shape and appearance but it won't necessarily lead to fast weight loss showing on the scales as muscle is 'heavy'.
2. If you are overdoing the exercise, your body will hold on to a lot of water so that it can repair itself. All exercise causes tissue damage, that is what makes muscles stronger - and to repair that the body floods the tissues with water. So you could have lost fat but be holding onto fluid weight.
Although what you are doing will be improving your body in the long term, and is mostly definitely going to do your figure some good, the loss will be slower, especially at the point you are at where you are not very much overweight. If you like doing the workouts so much then it might be an idea to switch from measuring your weight to taking waist/hip/arm/leg, etc measurements? Or take photos every few weeks so you can see your body changing. Alternatively, i'd suggest cutting down the exercise or at least making your workouts a bit 'easier' to give your body a break.
Finally, remember it is going to be slow as you are nearing goal. Keep going onwards, and you WILL get there - even without the changes i suggest above, just bear in mind the reasons i suggested for slower looking weightloss and if you stick with it things will work out it's just going to take time. You can do this so hang in there!