Need help to loose last few pounds!

I'm a 19 year old student and started exercising intensely 3 months ago. I found the weight to go quite quickly, I went from 59kg to 57kg in 3 months however now I have found myself in a bit of a plateau stage and the weight does not want to shift anymore. I did go through a bit of a stage where I found myself giving into my cravings for about 2 weeks due to stress at work ect. I have no come to the point where I want to seriously continue to loose the weight to gradually get to 54kg in about 3 months time if that is doable?

Any help from anyone would be great as i'm starting to get annoyed by the lack of weight I seem to be loosing. My diet is now back on track and so is my exercise however I was still exercising with the time when my diet went a bit downhill although I can admit that the effort I put in was a bit of a mediocre attempt as it felt like I was just going through the motions.

Also it would be very helpful if you have any suggestions of new exercises which I can do as right now I am focusing on cardio, treadmill, elliptical, bike ect aswell as some toning exercises so anything new would be welcome with open arms.