She tells my dad everything she will tell him and me and him are not close!
1. Your mother will not "see the hole in your vagina" and she won't know you masturbate. 2. Your mother should be answering any questions and helping if you ask, but she should NOT be putting your pad on. How does she think you'll take care of things when you're at school or away from home? Maybe another adult woman in your life, or even your doctor, could explain to her that this is something you need to do for yourself.
You should tell her. She should help u and make sure ur ok. haven't u got any friends u can speak to about it? Or cant u ask her to not tell ur dad? and because its quite personal she might respect that u dont want him to know.