Help for balancing diet!

[grx]

Hello:

I can not gain mass because I have a serious problem with diet. It is divided in 5 meals, and this is the composition:
Protein: 128g [22% cal]
Carbs.: 280g [48% cal]
Fat: 80g [30% cal]
Cals: 2345

First thing is to find out how much protein I should eat. weight is 66kg, 19% fat and want to reach 70kg, 15% fat

Teh gym nutritionist recommended a diet with this composition:

Protein: 156g [25% cal]
Carbs.: 343g [55% cal]
Fat: 56g [20% cal]
Cals: 2500

As you can see, the relation carbs/fat is terrible in diet. current proteins % is not that bad, but there is a big difference respect the recommended intake (-28g). First, I would like to know why they stated 156 g of protein. I know a rule: 2g per kg of weight. That would be 2 x 66= 132 g, or if it is respect to goal, would be 2 x 70 = 140 g, but not 156g. When I know how many proteins I should eat, it would be easier carbs and fat.

Another question is how to know the total daily calories I should eat to gain mass? I know a rule: 500 + manteinence cals. I guess manteinence cals is 2000, but sounds like an average... is there a way to calculate them or is that ok?

So in summary, I need to know how many proteins and calories I should eat in order to gain weight.
PD.- I did try calculators from this website, but I got more confused.... would be helpful if you told me "how" to get the numbers!