What can be done to decrease attraction towards pornography?

Hello doctor,

I am a 26-year-old male, and I have been suffering from a very critical disease. I feel tense, stay in fear of a simple matter, my heartbeat grows fast, and I am always in doubt about all of my work, especially my religious work like praying. Let me give you an example, if I pray, I feel like my prayer is not accepted. When I walk on the road, I see one thing many times, and it happens always. If I read anything, then I repeat one word many times, although I have already read it. I always have doubts in my mind, although people tell me to trust them. My mind always feels sorrow. I cannot laugh at all as tension overcomes me, so I cannot be happy. I stay abroad from home and work in another country, and I am still unmarried. I have an attraction to pornography and girls to have sex. But I do not do it actually but I want to do it. I think about this kind of thing if I see any girl or any photo. Please help me.