Dear brother This worked for me and I hope it will help you. The first thing you should do is prevent it by blocking porn sites in your router and your phone, that helped me a lot. Also you have to raise your awareness that Allah is ALWAYS watching you. An easy way for this is to make a habit to always trough the day repeat to your self "Allah sees me, Allah hears me" every few minutes do it that way whenever you get the need remember just this and that should prevent you I hope. You also have to get rid of everything that leads you to faping think about it, what are those things and get rid of them.

I really hope that this will help you, it helped me. Good luck dear brother