I am so sorry for your loss. To me my pets are my family and loosing them is like loosing a piece of me. The two that meant the most to me were my two orange boys, Oscar and Boo. Cats who were my pillars of strength when I had none. Although Boo was the hardest one to loose. Oscar just went out in the yard one day and fell alseep, never to wake up. But Boo was suffering with feline lukemia, and had to be put to sleep. I stll miss both cats dearly, despite it being 7 years since Boo died and 14 since Oscar died.
You will go through a time of mourning. Make sure you have a shoulder to cry on, be it human or furry. My current cat Muffin, whom we got when Boo was still alive (and Boo I got when Oscar was still alive) has been a huge part of the healing process for me. As well as a caring husband. I'm not going to lie, it's going to hurt for a while but with each day you'll feel a little better. For each person it's a different time frame but don't expect it to just suddenly feel better.
Best thing to do is to be with family or friends that understand your pain. But also keep yourself occupied, what ever your hobby is do it. Hang out with friends. Go see movies. For me it was playing WoW and drawing. If you give yourself too much time to think about it you'll become depressed. I hope this helps in someway. *Hugs* (I'd post pics but I don't have any pictures of Oscar on my computer. D: Wouldn't be fair to post Boo and not him lol.)