Pornography and masturbation, if they've become a habit, have created psychological problems in your mind.  They've warped the way you see things and the way you do things.  You cannot simply flick a switch and change yourself back to how you were before they got to you.

You need help.  Psychological help from a licensed (and preferably Catholic) therapist.  If you cannot afford it (remember that health insurance will often pay for psychological therapy) then you might be able to find a priest who will agree to be your spiritual advisor.