Working on Bettering myself

I’ve been addicted to porn since the 6th grade and ever since then, its been an outlet that I tend to go to when stressed, anxious, or depressed. I am now 23 years old, with a beautiful girlfriend that I’ve been with for 3 years, she is the woman I plan to marry someday. For the past year, my addiction has gotten worse, and I feel as if porn isn’t enough. This led me to recently sext another female who I knew had a crush on me for awhile. I just confessed to my girlfriend about this whole situation, and to hear her say “I feel insecure, as if I’m not enough for you” hit hard. It really woke me up, I don’t want to go down this path. I need help, I am hoping I can better myself for my girlfriend.