hammer croal

Tried to trim a dead head off this hammer and accidentally went too far!! Is it going to be okay? Should I fill that area with reef super glue? Idk what to do. Any help is appreciated please!!!!!

Hey, I just got this hammer last thursday and it has been looking great until last night I noticed a few arms around the outer perimeter of the coral looked a little shrunken and deflated. Thats when I also noticed what looks to be dead arm with a missing tip? It has looked a little more...