I still expect to see him, hear him, feel his presence. This is normal and it is known as denial. Again, your brain cannot process the enormity of what has happened. It's just too much. So, you don't feel that it's true yet, even though you know that it is true. This won't last forever, it will last as long as you need it to, and your brain will gradually let the truth of the situation sink in when your mind knows that you are ready. You don't need to fight this either.