Sin sucks
Its can disguise itself as something good and yet you will know immediately afterwards that you messed up.
Overcoming this is hard. But like everyone else said, God knows that you’re trying and He will be there for you when you need Him.
Just don’t shut Him out. Sometimes you’ll push Him out of your thoughts for the fleeting moment of pleasure, only to be reminded of the sinfullness of the act.
Boredom, as everyone said (Isnt it great to have people who know exactly what you’re going through?) is a big problem. Its like the Devil is tapping your shoulder and saying “You’ve got nothing better to do!”
Ignore him and see that temptation for what it is. Think about where that temptation came from. And think about what that tempter is and what he stands for. Thinking about that may help in tandem with asking God for His grace.
In the Catechism of the Catholic Church it says this:
“To form an equitable judgment about the subjects’ moral responsibilityand to guide pastoral action, one must take into account the affective immaturity, force of aquired habit, conditions of anxiety, or other psychological or social factors that lessen or even extenuate moral culpability”
So perhaps it is not a Mortal sin in the case of addiction, but its still a sin and it must be rejected.
I recommend that you keep going to confession at least once every two weeks. Also, pray three Hail Mary’s a day for purity of mind, body and heart. Pray the Rosary, make the Stations of the Cross. and devote yourself to St. Joseph.
Trash anything that will remind you of the act, and remove any temptation. That includes swimsuit posters, etc. Surround yourself with holy images instead and focus on them during your time alone.
Practice self-control in other aspects of your life. Fast, skip watching a TV show, clean up a mess.
Just don’t let yourself fall. And we won’t let you fall either. Come back here if you feel like you need help, someone will provide some words of wisdom, holiness and perhaps simple distraction.
If you’re at home and you are bored, and that temptation starts to come up, do something active!
Run around in circles like a chicken with its head cut off. Lift weights, something!
Even playing games might help!
Using those temporary helps (distraction) along with the long term (Prayer, etc) will help you overcome this habit.
Just don’t give up, because the devil won’t either.