My cat died last night.....when will the pain subside?

My cat, Carlito, a delightful five month old ball of energy died last night. I think he got hit by a car. I saw him outside five minutes prior to hearing him cry out a few times. By the time I had him in his box ready to go to the vet, his breathing was heavily laboured, body limp and he died a minute or so late. I feel excruciating pain, more than when my grandfather died. I don't think I will ever laugh or smile again. Today, the house it quiet, his absence is deafening, my dad is teary eyed, my other cat is going in circles looking for Carlito. I feel like I never want to keep another pet because the pain of losing them is so great.When will this pain go away? Does it ever go away?