It is not a good feeling to know that you are not ready to die yet. It shows that you are still tied to the world and yourself and that you are not spiritually free. The Lord is not going to drag you into heaven if you are reluctant to go there. Therefore, voluntarily detach yourself from the world and yourself so that you may freely soar to God when he calls you. It might turn out to be quite a battle, but it's a battle you must win and you can absolutely win with God's help. Think of it as preparing for taking the happiest trip you'll ever have, which, of course, is true.