A.D., my thoughts are with you. You are not alone. We all grieve for the loss of our loved ones and that journey is at times a very solitary one. In many ways, we are all in parallel mourning for something. Be strong, but cry and scream if you have to. It helps.
I lost one of my closest friends in 2004 and it was and has been a long journey. I have lost many friends and relatives in my life, but this one hurt the most. If I had also lost a parent at the same time, I don't know how I would overcome it, but humans are remarkably resilient beings. The grieving process takes anywhere from 2-4 years to cycle and if you are unprepared post-traumatic stress disorder sets in. People die everyday, but it hurts different everytime. Science can only do so much for grief, other than wiping your brain...
Past the initial trauma of losing someone and the emotional rollercoaster that cannot be analyzed, what is most shocking is the moment you realize you will never talk to that person ever again and you enter a state of melancoly about their absence. It took me about a year to get to that. It doesn't really get easier -- just different every time.