I was a vegan for two years and I really enjoyed it. Then I got to a point in my life at which I wanted to do something else so now I'm a vegetarian. You should make your diet one that best fits you and how you feel. Listen to your body. The most important thing is to exercise drink lots of water and take really good care of yourself.
I'm very comfortable with the nature of life and death and that we come to an end. What's most difficult to imagine is that those dreams and early yearnings and desires of childhood and adolescence will also disappear. But who knows? Maybe you become part of the eternal whatever.