Should I still be in shock after losing my cat?

Is it normal to still be in shock almost one year after losing a beloved pet? My eighteen year old cat passed away suddenly several months ago and I still feel numb inside. I have tried to snap myself out of it by focusing on other areas of my life, that helps for a while, but then the raw emotion of the night she died hits me again like a ton of bricks. I am optimistic by nature but have become withdrawn and indifferent to everything since my cat died. I am not going to say it feels like I've lost a friend, because I'll get too many sarcastic remarks, but she did have a big personality so it's hard to get used to her not being around. Has anyone experienced similar, and does it get easier with time? Thank you.