Please help me to stop p*rn and masturbation addiction

Its been 2 years since i started doing this sin.I became a Christian 1.5 years ago.Everyday i Pray for help and almost everyday i read the Bible for the last few months but no matter what i cant stop doing this sin.The longest i have gone without it was 20 days.Even after knowing what Jesus had to go through for me i still go back to the same sin.I know God haven't given up on me since i am still breathing and i still have faith that he can free me but everytime i keep going back to that sin it feels like the faith and hope slowly fading away .I never had the courage to ask people for help but now I am asking you guys for help because I thing that God wants to.I really want your help and your advise.