Try putting a pressure gauge on your washing machine shut off. Now with all water turned off to your fixtures read the pressure,this would be called the static pressure. Now go open a faucet and read your pressure, this is called your flow pressure. If your static pressure is good, I would check a neighbors apartment on same floor to compare with, and your flow pressure drops then I would check the main valve for blockage,( I would check the main valve first to make sure that it is fully open. If when you open faucets for the flow test the pressure gauge does not fall, then check your aerators