How porn is ruining my life and relationship

Porn and masturbating is something that I had discovered and have been addicted to at a young age. I masturbate 1-2 times everyday for 10 years and I have never been able to tell anyone about my addiction until I met my girlfriend. I am becoming extremely depressed and fatigued after I masturbate and I need a change in my life. Porn is ruining my life and relationship and I want to quit for good. I found this community from a friend but other than that I don't really know where to start. I do know for sure that I want to eliminate watching porn and masturbating from my life forever no matter how hard it is.