My father passed away. How do I move on?

My father died today. I am still in disbelief. He started feeling very sick and went to the hospital, and seemed to be a bit better, and then got up from his bed with a nurse, and died. I came in just as the doctors were running into his room to try to resuscitate him. I have taken care of my father for years, but most of all, he was my best friend, my rock, my sunshine, my advisor, my mentor, and the best father anyone could ever have. So, I feel right now like part of the world is gone. How do you go on from here? It's the most different feeling to have not only lost a parent, but to have lost someone to whom you were so connected. I know I complained at times about how hard it was to be a caregiver, but I don't regret a minute of it. I think I did my best and I know that my father felt like he had me to rely upon. My husband also helped and he's devastated by this, too. I feel right now like I am lost and alone and overwhelmed with sadness. How will I go on from here? My heart is so heavy.