Catholicism, as you would expect, makes no sense.
Pay no mind to it.
People who have more frequent ejaculation have a 70% chance of NOT developing problems with their prostate-including cancer. It also promotes psychological well being, reduces stress, promotes mental balance, promotes cardiovascular health, and the list goes on.
I used to be poisoned with all the trash they feed you at private school. The priest at my high school (very long time ago) put emphasis on masturbation and hell; that is, if you masturbate, you go to hell..
I find it hard to believe that god will burn you FOR ETERNITY (hello, catholics, do you not find this preposterously absurd?) for using WHAT HE GAVE YOU......
At any rate, you will lead a much healthier life if you abandon the question of morality as relates to masturbation. And avail yourself of never asking for moral advice or acceptance from religious people; quite frankly, they have the lowest IQ on earth.
Good luck.