I just read what you wrote about your research. The one thing you didn’t mention is that each soul has friends and relatives that they too lost and are waiting for them on the other side to help them through their journey. So as painful as everything is that the neshama might have to experience she is not alone and is being guided through the process. She might have been greeted by her parents or grandparents or other loved ones that she loved and missed for a long time. As much as Hashem takes away he also gives. So please don’t ever feel that your friends are alone, they are never alone.
I am sorry for your pain. It is a tough time for you losing two close friends, not understanding why and not having answers. It is a shock and you will go through the grieving process. Please don’t try to fight it, it is something that you have to do. If you put it off it will hit you later.
EDITED