if you are on a calorie restricted diet like the one you have explained above, i wouldnt worry about getting too big, your gona have to train you ass off just to hold on to what muscle you have. as i mentioned im not the best person to help with this, but if you are training consistently and hard i dont think that 2300 cals in a day will be enough for you, youll end up losing a lot of muscle.
also be sure to add a casien protein shake before you go to bed. i dont know when you take the shake described, but if its after training i would try to substitute that milk for water. adding milk to you powder tends to mean it will be absorbed slower by the body, where as after training you want it absorbed as quick as possible, also try and get about 25g of protein before you train along with some complex carbs.
hope ive been of help, built will hopefully be along shortly to go into more detail.