I have a lot of respect for someone who went through so much. At a much smaller scale I think that one can be depressed when pursuing a strong goal comes to an end. It could be a project at work or a degree. I have been depressed in such situations. I think being able to let go the past and move on to a different life can help. In my case meditation helped me realize happiness is not so much about goals but more about being satisfied with simple things.