My Beloved Cat

I accidentally  ran over my cat today, & am just devastated about it. She was 17 years old & in good health. When I come home in the afternoon she is always waiting for me on the porch. She evidently walked off the porch & sat down in front of the car & I didn't know it. I felt the car go over her & immediately jumped out to get her but she ran from me. I hurried into the house to call the vet & see if he was still at the office. He was & he said to get her in as fast as I can, but when I grabbed a towel to wrap her in & went back out she was dead. I am just wracked with guilt & heartbroken at the same time. She was my best friend. I miss her completely.