I'm sorry to hear that this happened, and that it feels like something that's coming up again and feeling upsetting.
You're not really "supposed" to do anything - you're the boss, and you can decide what you want to happen from here. Does anyone else in your life know about it? Would you want to tell them about it? Do you feel like you need some extra support, from a counselor at school or an outside therapist? Or do you not want to share anything and instead focus on feeling what you feel and taking extra good care of yourself? All of these are valid options, and you're the one in charge of what happens next. We'll be here to support you along the way. <3
Just in case you haven't read through it, you might find Blinders Off: Getting A Good Look At Abuse and Assault
to be a helpful as you're thinking about this stuff.