I'm seeing a guy that I'm pretty scared of again, what should I do?

6 years ago, when I was 8, I went to a scouts camp. I was very little and extremely naïve, somehow I attracted the attention of a 12 year old boy, who took advantage of me being so naïve. I won't go into the detalis to much, but the bottom line is that he did smth to me that I didnt have the ability to consent to, and repeatedly protested against (it wasn’t rape, but still). For years I pushed what happened to the back of my mind and ignored it at the best of my abilities. For some reason everything has kind of come back up, while my brain automatically tries to forget it, to the point i cant remember his face, i still have panic attacks and flashbacks of what happaned.

This up coming weekend we are going to have a big camping trip with all the groups (his in the older group thank god) and we usually mix the groups, which mean I will see him again, if not have to play and work with him.

Im not scared of it happening again, because he has ignored me since it happened, but I'm scared of being triggered and crying. I havent told anyone, bc there's no one I trust and I cant tell my Mom (i have my reasons). Skipping is not an option since my Mom wants me to go. I already asked a girl I trust to look out for me, without explaining anything to her, apart from doing that I dont know what to do!