Re: A relapse of sorts
You are incredibly right, talking about cutting ourselves to anyone is very very hard. But you are so on the right track, the fact that you recognize this as a slip up and want to talk to your mom about before she notices, is so awesome, it shows so much growth on your part.
What you might say is something like, "Mom, I realize this will be dissapointing and difficult for you, but I had a slip up. The (insert whatever here)pain, fear, anxiousness built up so quicky and before I realized it I was out of control and had handled the situation with my old coping mechanism...cutting. I didn't want you to just "see" them and be hurt. I wanted to tell you myself because doing this will be a big part of why I don't cut next time. Please don't panic and think that things are back to where they were, because they're not, I slipped, lost my bearings for a minute....but I'm fine and will get control over my illness again. I love you mom and don't want to hurt you."
Something like that. make sure that she knows that you understand you'll have to try even harder to get back on the right path, and your up for the fight, because truly in your heart of hearts this is not what you want....you don't want to pick up a knife each time things get bad....
She may be angry, or hurt, or cry or yell, there's no telling what her reaction might be, but regardless do what you plan to do and take ownership and then get back up and back in the battle to avoid cutting. Go back to some of the things you've learned in therapy, safer coping techniques....perhaps some extra time with your therapist might be a good idea.
But don't worry yourself sick about it, you'll be okay and so will she. Your strong and you can do this.
Yell if you need to talk,
take care and stay safe and strong,