Well to be honest, I'm not 100% sure its the filter or the injectors. BUT those are possibilitys, a clogged fuel filter will make you push harder on the gas to get the car up to speed, making you use more fuel also.Fuel injectors that are clogged and spray uneven will give a loss of power and a slower throttle responce.
It might not cure your problem but it isn't bad to try.
Another thing it could be is a clogged Catylatic convertor. Or a very dirty air filter.
Their is a way that "I" check fuel filters but idk if you would want to check if its clogged. The way its done is take off the filter, pour out all the fuel, sit it out in the sun and make sure its dry. Use your mouth to blow in the inlet of the filter, and if your cheeks puff up and its a little hard to get air thru, it is clogged. If you can get air in the filter without your cheeks puffing than it is fine.