Clitoral stimulation is completely fine. This will not rupture the hymen inside the vagina. several things can rupture this....tampons, a finger, penis, vibrator....many things that can be put into the vagina can rupture it. There isn't a way to tell that it has been ruptured without a full pelvic exam...the kind a doctor does during a papsmear, etc.
I am not sure how your culture is, or what your beliefs are, but you should have rights over your own body. If you masterbate, not will be able to tell...but you. As long as you stay outside of the vagina.
You can masturbate with a vibrator on the outside of your vaginal mound (not penetrating the vagina) and press to find the clitoris. It might make you feel like you have full rights to make yourself feel good. It won't harm the hymen.