Well, one thing I do know from my own experience,is that it does not help to judge yourself for what happened. You can't change feeling bad necessarily, but keep an eye on the thoughts that come along with that guilt. A lot of time they are thoughts that you "shouldn't" have done that or telling yourself you're a bad person. Try not to give these thoughts much attention. It is difficult, but they do no good for you. They will only make it more likely for you to do it again. It sounds like you did a good job not self harming for a while. Thats great! That's a hard thing to do. Slips happen. No one is perfect. You tried other things first, that's also good. Be kind to yourself, you deserve some grace. You are not perfect, no one is. Since we are not perfect, we will make mistakes. This does not make us bad people. You did the only other thing you knew to calm yourself down. It wasn't the healthiest thing, but as humans, we go back to what is familiar. Self injury is a coping skill, again, not a healthy one, but it is. Try to give yourself some credit for trying things before using self harm. And moving forward, try adding a few more things to your list to try next time you get upset. As for your boyfriend, if he is worth having around, he will be concerned. He will want to help. If you telll him and he reacts badly, then he is not worth your time. You don't have to tell him, but if he asks, it might be easier to just talk about it. Self harming does not make you any less. It doesn't make you worthless. You are a person. You are alive, this, and this alone gives you worth. Nothing you do or say can take that worth away.