What will happen if I tell my therapist I self harmed after group therapy?

I (26F) had really hard group therapy session this week. I felt really bad because I had panic attack after one person from the group said something that was deeply triggering for me. Towards the end my therapist asked if I feel self harm/suicide urge and at that time I didn't, I came back from it, I was dysregulated but had no thoughts bout hurting myself. After the group ended I walked home (1 hour walk) instead of taking a bus so I could calm down.

Two days after this I hit myself in the face. I feel urge for other things but I'm able to ground myself. The reason why I did this is mostly because of the triggering thing.

I dont want to admit to this in the group because I dont want to upset the person that said it (I dont think she meant any harm) and I honestly feel like dropping the group right now but I see my individual therapist (from the group) next week and I know I need to tell her this. I am scared she will judge me or say that I overreacted or say that I'm making victim out of myself.

What is the procedure for things like that? I feel like I fucked up big time.