I've fluctuated in weight since I started taking SSRIs. I eat relatively well (No fast food) and exercise 5-6 days a week. Try tweaking your exercise regiment. Many people just run on a treadmill, but lifting weights is incredibly valuable when it comes to weight loss. An increase in muscle will boost your resting metabolism. Try some sort of circuit training with weights and body weight exercises.
Pull-Ups > Push-Ups > Body Weight Squats > Planks
Ensure to have adequate protein intake. I've also read that Fish Oil helps with depression and weight loss as well (They are Omega 3's, which are good fats). Try supplementing with that (I personally take 2g per day).
Stay away from processed carbohydrates. For example, if you're going to eat bread, stay away from white bread and try a whole wheat type or even a wrap.
I hope that this helps.