I have heard that sometimes making promises to other people not to SI can sometimes make things worse. I am not sure if the things surrounding that promise may be adding to your discomfort now. From what I see from your post, you seem guilty because you feel you may have let him down by self-harming. In some ways that may be distracting you from yourself and your other feelings because you are more focused on what he will think and feel about what you have done.

Maybe try redirecting some of that energy back to yourself. Understand for yourself why you want to stop self-harming rather than making a promise to someone else. Sometimes it can be good to have an accountability buddy, but ultimately you have to want to stop for yourself. Maybe you can also think about what led up to this relapse and how you might prevent it in the future.

Also remember that self-harming has probably been what you have done a lot of the time when you struggled with difficult emotions. Even though you may be learning new coping mechanisms and ways of thinking, self-harm is an addictive behavior and it will be difficult to avoid it all the time.