I don't know if these count as sexual abuse, but...
When I was a child (about 9), a boy on my bus would corner me into a back seat and touch my breasts and the whatnot. I don't like being touched, so I felt really embarrassed and horrible about it even after saying no and leave me alone multiple times to him. The bus camera caught it and sent the boy... two seats up from me.
Then in seventh grade, a different boy grabbed my ass and stalked me. This one only got reported because it happened in the middle of gym class and a bunch of girls told the coaches about it during change time. Boy didn't get punished in any way.
I've never been raped or digitally penetrated, but I've definitely been sexually harassed.