As above,
Also, the snacks is something you definitely want to cut out altogether if possible, you want your main meals as usual, you want to plan the meals so you just about get hungry, not as hungry so you're starving and definitely not so your feeling full.
It is worth to note I am not an expert however,
To lose fat mass, you need to be using fat stores as your energy as such,
So for instance, if you're daily calorie intake is higher or equal to the amount of calories you burn off, then its going to be hard if not impossible to lose weight, there should be information and calculators online where you should be able to calculate how many calories you burn off daily, including calories burnt during work, sleep, exercise etc.
Depending on the exercise as well, even though your weight may not be changing, this doesn't necessarily mean your body fat is not going down, it could be turning to muscle.
I found swimming is a very good way of exercise, you can very easily control the intensity of a work out, and it works out your entire body rather than just your legs for instance and really gets your heart rate up, you're being naturally cooled down by the water, there is no shock on your body like running for instance (as your joints take a shock every step you take) and its very refreshing exercise.
The downside is with some people, they may not feel confident, it can cost to go and it can be inconvenient (you have to go when the pool is open, travel to the center etc.)
Hope this may be of help