When you think that you watch too much Hentai, the only solution is going to watch regular porn. This good to have variety in who source of lust. Dont forget to use your imagination sometimes.
When I was underage, my mother didn't want that I watch porn, but I didn't listen and continue and now, I'm a 21yo otaku without girlfriend that doesn't know what he want to do in life. If you dont want to finish like that, never watch porn/hentai again!!!
If you want to finish like me, first, if you dont want that your parent know what you do, use a browser that they dont know that you have (Maybe Opera). Second, check your porn in the middle of the night or wake up early in the morning. Another good time is in the afternoon, when everybody work / study / masturbate.
Dont forget, if you masturbate, you'll become deaf or blind.