Why it seems like I'm paying more than the others ?

First, you are not paying more than others. You are just paying smarter. 

Everything is about the type of your charge: "Provision sur charge". More information here

Since last year, charges such as electricity, gas etc has been increasing a lot. 

To be as close as your real charges consumption, the landlord has decided to increase the cost of charges from all available bedroom. Not from the occupied bedrooms because the actual tenants must agree first.

So you will see a difference in a few euros and feel like you are paying more and for the others. 

But it doesn't work like that. 

Every month, you pay for charges, but it's a provisional cost. The real cost of your expenses can be calculated only from when you move. (Numbers are checked from electricity/gas/water meter). 
If you consumed more than what you paid for, you will be billed. 
If you consumed less than what you paid for, you will be refunded.