How often do you think about dying?

Ever since I was 16 I have wanted to die. I'm not suicidal because I know I will not get into heaven if I commit suicide. I don't know if this is normal to want to die. It's something that I think about a lot. Almost every day. I would like the Christians to respond to this, only because you can relate to this subject more. I have found myself asking God to take me. There is a part of me that is still scared, but for the past year I have been trying to come up with things I can do to wear I feel like I have served my purpose in life. Like donating bone marrow or a kidney, I've even looked into being a surrogate mother, just to try to serve my purpose so the Lord will take me. Is this normal?