Depression leading to death. Situation?

Friends are undefined relationship in one's life. Just as co-passengers in a train journey they get off when their destination arrives.  Same has happened with your friend who has moved on. Ask yourself why aren't you moving ahead, you too have your own dreams, aspirations, priorities etc. You too are capable to make new friends as you walk through your life's path. Looks like you are possessive and focusing more on THAT friend and ignoring many other relationships around you who are waiting for you. Count on the blessings and move on. Move away from the emotional domain to intellectual domain and look things differently.  You can seek help of a Counselling Psychologist who will empower to handle the situation and move ahead in life.

Live for yourself. Find out whom do you want to become in life. And reflect, where are யு, in that respect. You do not have the privilege ti leave, before completing your wish and dreams.

For a detailed understanding,  consult a psychologist either online or offline.