One cannot change these habits by our will power only. Control your breath to control your body. Google abdominal breathing learn it and practice it for 10 minutes twice a day. Use this breath when you are sexually aroused.withing 5 to 6 breaths your arousal will diminish. this way you will be able to control your sexual urge.Deep , slow and even breathing is the best way to control your anger, sex,anxiety etc. Be patient to get results.
You need to change your life style completely. Take help from any professional. Psychologist can help you.A psychiatrist can help you. Using I can't will not help you at all.
Have you spoke with a mental health professional/ doctor about your concern regarding your porn addiction? If you haven't, that would be a good place to start. Speaking with a doctor, would be a confidential way for you to seek help and be able to receive treatment without your family and friends being involved.
Good Luck