Tired of hurting those around me and suffering because of my addiction

I'm a recently engaged man who is currently graduating from grad school. I've made it through one of the hardest medical programs in the world yet I don't seem to have the ability to beat this addiction and now I see it affecting everyone I love around me! Its making me struggle in every aspect of my life! From how I view my amazing fiancé to my overall motivation for anything, to going on other cam sites and looking for woman masturbate with. I feel like i'm one of the worst people in the world and feel like I live a lie. I hate it. I want to be able to have victory over this addiction but there's a part of me that secretly loves watching porn and craves it. Its terrifying to me that this part of me exists.

My two biggest guilts have to be that I have done sexual acts over the internet with woman who aren't my fiancé. I won't marry her if I can't stay true to her. She deserves someone who will be true to her and no one else.

The second guilt is how it has affected my spiritual life. I feel almost adversarial with anything related to my religion. My faith is my greatest comfort but also my biggest frustrater. There's a need in my church that I feel i could help fill but I don't ever step up because I'm terrified of being in a leadership role when i most definitely have no business being there.

I want to beat this addiction for my Fiancé, myself and my God. I want to have my desire to do things back and my desire to work hard not quit on things! To better myself and have this guilt of my shoulders. To be able to look my fiancé in the eye without wanting to cry because of the betrayal ive done to her.

I need help.