Must I make up past prayers that I do not remember and whose number I do not recall?

There is no sin upon you if you missed a prayer due to forgetfulness. What is obligatory upon you is to make up the prayer if you are certain that you missed it. If you are not certain that you missed any of the prayers, then you are not required to make them up. If your re-performing of prayers stems from obsessive whispers (waswasah), then do not pay attention to them and do not repeat the prayer merely due to doubt. Rather, consult specialized doctors.