Up the intensity of your workout. I'm not a born jogger or runner (i absolutely loathe jogging) but try and includes bursts of jogging for 30secs or so and slowly increase.

I think what is happening with you is muscle gain. Just go by the tightness/loseness of clothes

Water is really important. I agree with the others. I find drinking water hard but i have this phrase which i think about when i need to drink another glass of water ..

The more i drink, the more i shrink

I've got 7.5kgs to lose and the plateau is driving me crazy too.