Life is about many things and about different things for different people. It is also possible to have your life touched by tragedy at one point and lead a rich and fulfilling life at another point. So I wouldn't give up hope for your child just yet.
My dd did try to kill herself as a teen but that was part of a MH condition that I now realise (having looked into it more deeply) is hereditary in my family and has afflicted various family members for at least 4 generations. Could have been any of us. The difference was that growing up now and not in the 1900s or 1940s or 1970s her illness was recognised and she was given support that means her chances of making the most of her life and handling her condition without burdening her family are probably far better than those of previous generations.
If you ask her now, her life isn't about her MH condition: it is about her dreams for a career, the training she is doing, her friends. The depression and anxiety in the background are like any other chronic illness (and she has a physical one too)- something that you work around as best you can.
As for my son (currently 19), he too has seen his fair share of tragedy- friends killed in accidents, or taking to drugs, or in various ways struggling with life. He is finding it difficult to know what to with himself at life and hard to find work.
But what generation didn't go through those things? His grandparents were young during the war, his greatgrandparents lived through starvation riots. There may not have been much cocaine around when my grandparents were young, but there was plenty of alcohol instead.
If you have a child, you are basically accepting that they will grow up into real grown-ups with all the suffering and need for courage that that entails. And there is great reassurance in suddenly looking at your adult child and realising that they are brave, strong, loving people. When my son was a little boy of 6, he wanted to jump out of the window because he had just learnt (by accident) that his sports coach whom he had adored had been killed by her boyfriend. Last night he ran out of the house in the middle of the night because he heard the sounds of a woman in distress and thought someone was being attacked (turned out to be a neighbour in labour, so no rescue required). I have raised a good man: I do not regret it.