Yeah you dont need to tell anyone. The important thing to do is figure out if you could have done anything to prevent it. But not to obsess about, rather, use it as something to learn from and grow on. If you truly believe that there was nothing you could have done then it's just good to accept it and move on. But spending time feeling upset or angry isn't gonna help in any way. Idk if that helps. I want through something like this right before high school with 2 of my closest friends. I spent a lot of time feeling sorry for myself and mad at them. But in this case it was mostly my fault, I eventually understood that and used it to change how I went about all my relationships.