I don't think you'll struggle with it for the rest of your life and I say that because I was in the same position as you were in high school. My depression started my freshman year and that's when I started burning myself then cutting or hitting myself. I totally understand what you mean about the release it brings. It is a release. It's almost like a high. But when I finally left high school, and even though I was still pretty much feeling depressed and anxious all the time, I was embarrassed by all the scars on my arms. People look at you differently. And I was tired of trying to hide them. There are other ways to release stress when you feel like cutting. Break something, (nothing of value of course) like maybe glass bottles. Scream into your pillows, snap rubber bands against your wrist (that seems to help most people) hold ice cubes. It all sounds strange but these are things that many people do when they have cutting addictions. You're so young and this is so sad ): I hope you get better. Feel free to pm if you want.
So young but so much wonder....It's like your head gets lost somewhere else. Cutting to me was like my one step back behind the run. I haven't started again but it's always on my mind. My depression was like a war with myself....It's not a struggle you'll have for the rest of your life, but a memory you'll carry on. A quote that I kept in my mind while quitting to cut was "If no one has faith in you, learn to have faith in yourself." Best of luck.