What should I do about missing the make-up of missed prayers after ghusl from menstruation due to laziness, and should I make them up the next day, or should I continue making up two prayers a day? And what should I do about practicing masturbation without ghusl for an unknown period of time due to fear of my family?

There is no specific time for making up missed prayers; rather, it is obligatory to make them up at any time of day or night, as much as you are able, without negligence. You must hasten to continue making them up at any available time.

Regarding the second question, you must make up all the obligatory prayers you missed after being in a state of ritual impurity (janabah). If you do not know their number, you must continue making them up until you are certain or highly confident that you have made up what you owe, because prayer is not valid while in a state of janabah if one is able to perform ghusl. It should be noted that masturbation only necessitates ghusl if semen is discharged.