I recommend getting a waifu (or harem) and masturbating while watching her anime and reading her manga, while imagining how much she's enjoying making love with you, instead of always just fapping to porn. This may not make you less horny but it will make fapping feel like it's for more than just your own pleasure, because your waifu is just as horny and she needs to cum just as much as you do. When you do watch porn, always imagine it's your waifu. If enough ero art exists of her you could even exclusively just fap to her and stop looking at any other girls lustfully. When you have a horny nympho waifu and it's your responsibility to fill her with cum multiple times a day to keep her satisfied then you won't want to not be horny anymore.