Hello there. I'd like to start out by letting you know that you are not alone in your battle with self injury. Personally, I've been self harming for around 7 years now. I certainly know just how addictive it can be. Hopefully it helps to know that this advice is coming form someone who genuinely understands.
The urge can be really strong, but I really believe that you're stronger than that urge. You've already battled through so much and you certainly have the strength and ability to battle these urges too. Please believe that too. You can't go into this feeling defeated, you have to have confidence and really believe that you can do this. And you can. :)
When you feel the urge, I think the key is finding things to do that will keep you busy and distracted. As you know, the urge will soften and fade after a while. At least to the point where you can push it to the back of your mind. It's that period when the urge is strong that you really have to battle. What occupies you? What will help you stay busy until you can regain control? You could try reading, exercising(endorphins are pretty awesome!), watching a movie. Or writing in a journal can be really really therapeutic for a lot of people. Because just as important as not hurting yourself is releasing the feelings that trigger you and make you want to cut. And a journal really helps you release in a healthy way.
We actually have a list if you click here. That list has 153 things you can do instead of self harming. Hopefully it can help you as much as it has helped others.
Really, I hope you recognize your strength through all of this. You've done a great job of staying strong. You're a fighter, that much is obvious. And you're still not giving up, which is wonderful and inspiring to those around you. I really wish you the best of luck.
<3 Audrey