Irina, you have nothing to reproach yourself for. The death of loved ones is hard to bear. The interest of others is understandable: this man was supposed to live for many more years, but turned out to be dead. It is especially difficult to accept the death of a young person, so we are trying to find justification for what happened, asking about the details. When we learn about the murders, our picture of the world changes, and it takes time to accept it.
There is nothing strange in your behavior, you have not committed treachery. You took a short vacation for the funeral, but it takes more than a few days or a week to really recover. You did the right thing when you told about what happened. At that moment, you especially needed the support you received from your colleagues.
It’s also very hard for the friend’s girl now, she has to accept and realize what happened. Usually we don’t have much experience in how to support people in such a situation. Therefore, do not scold yourself for depriving her of something, you yourself have lost a friend.
There is an important meaning behind farewell rituals, but in modern Western culture, these traditions are becoming a thing of the past. Now it is not customary to grieve in public, everyone wants to “hold on” to those who have lost loved ones. You may have felt a strong sense of shame precisely because death is now hushed up.
People who have lost loved ones often note that those around them seem to shy away from them, avoiding meetings in private. Many do not know how to express sympathy, feel shame. Death becomes an intimate matter — you write about it too. But while we mourn for the departed, even for those whom we did not know, we remain human. Do not be afraid that you have opened up too much, made others worry about an unfamiliar young man.