I am so very sorry for the loss of your son. My son, Tim, was murdered on June 20, 2012 by so-called "friends" during an argument - a friendship gone bad, from what I am learning. It has been over a year and I am still learning details - only in the bits and pieces I can handle. I do know he was shot several times, chased down and stabbed. I still cry (as I am now) thinking about what he went through.
I understand the misery you are going through. I know the immediate, devastating pain you are dealing with, as well as the long-term heartache that follows. Nothing will fill the emptiness, and that's ok. They are our sons and that special love can never be replaced. It will get easier. It will be different. It doesn't mean you love your son any less - it just means you're alive and you're a survivor. I love my son and think of him EVERY single day. I love him and miss him. But I have a daughter and her children - I must hold myself together for them. We do memorialize my son on a regular basis - and my son's nephew and nieces are an active part of this (we have sent messages in a bottle into the ocean, sent off Chinese lanterns with messages to my son written on them, released dove helium balloons with messages written on them, gone to a local grotto and lit candles for him, toasted him with our dinner drinks - even if it's milk/water, and celebrate his birthday with a birthday cake). We do everything we can to keep his memory alive.
I'm not saying I don't feel the pain - I do, God knows I do. And we still have the trial ahead of us - which terrifies me. And there are moments when I just break into tears about his murder with no apparent trigger. Our worlds will never be the same - we have experienced the worst of the worst. But we will survive. Hang in there. You are not alone. I am sending prayers to you....