Calorie amount help?

Hey guys!

I need some advice...
So, in January I decided to start losing weight and I went from 210 lbs to 156 lbs. I limited my calories to 1200 and I didn't excercise. Once I reached 158 my weight loss stopped for about a month so I started incorporating excercise into my daily routine. I have a sedentary job and I excercise about 2 hours 6 days a week with a combination of weight training and cardio. My trainer told me that the weight isn't coming off because my calories were too low he told me to increase my calories to 2000 and burn the defecit from excercise. I took his advice for about a month and the weight still isn't coming off and in fact I went from 156 to 159. He claims I gained weight from the muscle I'm building but I'm not sure. I don't want to undo all of my hard work from this entire year... Can you guys give me a calorie amount that I should follow to reach my goal? I want to be 125 lbs I don't care how long it takes so I don't have a time limit. I'm 22 years old, and female.

Thanks so much for all of your help!