Another guy in here linked this article on porn addiction (
https://oceanrecoverycentre.com/2016/07/the-ultimate-guide-to-overcoming-internet-porn-addiction/). I would encourage you to read it so you can understand what is going on in your brain and why the urge to access porn, masturbate and orgasm is so strong in you currently. Then you need to work on resetting and rewiring your brain so you can break away from this. Which is the 90 day goal you often see others working towards. Porn is a destructive force and will never be helpful to you in your life. Courageous of you to recognize a problem and want to address it while so young. The sooner you can get into recovery, the better you life will become.
I would also say that defeating this addiction is not something you are likely to be able to overcome by yourself. Working in here with the support of others is a great step. Don't know if you can share that you have a problem with an adult in your life who could work with you at home to help. A therapist/counselor would be of great help if that is accessible to you.
To control yourself from porn, you need to get away from it. First is block your access to online porn with a filter and ideally having someone else control the password or access. If you have other resources you use, i.e. magazine, videos, etc., get rid of them. You'll need to come up with some strategies for what to do when you start getting urges to PMO. Lots of good ideas in here from lots of folks. Exercise, cold shower, reading, prayer, talking to an Accountability Partner when it's getting rough, etc. Spend your time in something much more productive than porn and jerking off, which when we get in that zone or trance, can just take us away on that path for hours. Focus on the present - looking at 90 days or 21 days or whatever can seem overwhelming. Take it a day at a time, even an hour at a time to start. You can do it for the next hour, and then the next hour, or you can power your way through today, and power your way through the next day, etc. After a period of time you will definitely start to feel better, less strong urges, brain fog starting to lift. Don't let your guard down then, but recognize that you are being successful and making progress.
And the girl who left you, her loss. Conquering this porn addiction will lead you to a much brighter life. Working on being the best you, and the right relationship will come your way. The likelihood of who that future parter is, is probably someone you haven't even met yet. You are a worthwhile person. You can do this.
