I’m speaking as a person that is currently learning about being a good catholic. I’m currently a 21 year old female that would do that a lot a few months back, but when I realized it was wrong, then I slowly but surely kicked the habit. It wasn’t easy, but what helped me is getting rid of the source and putting that excess energy to use in exercising, learning how to be healthier, etc. At first it wasn’t easy, because I didn’t want to admit it was wrong. It honestly took me a while to do so, but one day I decided that enough is enough and no more, so I focused more on other things that are more important to me like work, education, and health.
And to be honest, I feel better than I ever have about myself. I also had the extra motivation to change that when I realized that both my boyfriend and I having that addiction didn’t really help to keep us together. I felt insecure because he’d look at other women in such an intimate form and he really hated himself for doing it. It’s just no good when you’re trying to make a relationship work and when you know it’s not morally right. Either way, pornography/fantasies/etc., only put unrealistic expectations for sex, and that could eventually lead to you falling apart with a person you value very much. I’ve seen it time and time again when a woman or man in a relationship feel insecure about themselves because they cant seem to satisfy their partner’s needs simply because their partner holds unrealistic expectations for them.
I guess what I’m trying to say is, just get rid of the source and focus all of that energy into something more productive and useful to you. It’s not an easy process when you go cold turkey in any addiction, but the results in the end are soooo worth it. You’ll feel so much better and feel so much closer to God when you’re not giving your attention to something that is so harmful to oneself.
Edit: Keep praying and going to mass and doing things that make you feel closer to God, WHILE you find other things you can focus on. The more things you have helping you, the better the chance of you beating the addiction.