I want to fix myself

Hello, this is my first post here, I actually heard about this site from a doc series called "Dark Net" and I didn't know there was a community out there with the same issues as mine. So here is my story. I started watching porn and masturbating when I was 8 or 9, and have been doing it regularly for around 15 years. No matter how many times I try to stop it just takes over my mind, like i'm a different person and takes control and makes me watch and do it. Then when I am done I feel like I am a horrible person and I just feel gross for it. It has shaped me for what I am today in a way and i'm not proud of it. To think of all the time I could have been doing something different and such. Even when I got a gf I didn't stop. It was good at first because we were like bunnies in the beginning, but even then after we were done I would still go back and watch and do it. I noticed my sex drive went down and masturbated more. We got married, now its pretty much all I do. We pretty much never have sex anymore and I know its completely my fault. I blame it on me gaining a little weight or I say i'm tired. But I know what the problem is. I have a monster inside me and I can't get it out. Even now when we try, I can only stay up for so long before I lose focus and just want to watch and do it myself. I need help. Really looking to better my life and rid this demon that has been inside of me for so long. Thanks for anyone that listens.