I know I have to make a formula corresponding to my values that would allow me to calculate the current and voltage, however, if these "values" are not stable, how do I then to calculate current and voltage?
Which values are not stable and what range are they in? We haven't seen the output you get yet, so you might have to show that first. I currently don't see yet how you would calculate the voltage or current from the rectangle signal you get on the digital inputs. The phase offset to calculate the power that is used seems to be clear but both voltage and current rectangle waves should be equal to the frequency of your system (60Hz I guess).