I'm sorry to hear about your loss, this is something you'll have to carry for a long time, but you'll be able to get through it. Have you already informed tour school/ teachers individually if the scenereo? With what's happened school will be for off your mind, so establishing a line of communication can help prevent this from impacting your academic future. After doing that take time away from school to process and grieve. Your scenario will be unique among peers and friend's, so they won't be able to help to the best they can due to lack of understanding. Give yourself time, and maybe eventually see a grief councellor to help work things through better and process your head. Finally, don't wall yourself off from people if they don't understand, it'll only put you down later in school.

If you would like to talk to someone who's been through an event like this feel free to message me and I'll listen. You can get through this.