You are strong, it takes a lot of strength to talk about your feelings. Self-harm is a vicious cycle, you have to get it before it gets you. The times you don't want to call anyone are the times you gotta make yourself do it anyway. I am going through the same situation with wanting to stop but not wanting to stop at the same time, it's very difficult and its confusing, know that you are not alone. Call your therapist (ir whoever ran the group) and see if she can help you. Keep your head up.
If you ever need someone to talk to feel free to PM