I feel like im betraying my old dog.?

1 year ago my dog had kidney failure couldn't stand, losing weight and wouldn't eat. The final day I had her June 17 2010 I was in my room watching tv then I heard my mom scream. I ran outside and saw my dog having a seizure, I was there the whole time with her petting her and waiting for the cops to carry her away on a stretcher. After she was gone from the house, she was in the vet room and I was at home. The vet said they had to put her to sleep. My dad came home, and told us the news. I was crying hysterically for 1 or 2 weeks and now its been almost a year and now I want a new dog. I asked my mom and she keeps telling me that im replacing her....what should I do... R.I.P Chi Chi June 17 2010 Shih Tzu/ Jack Russell Terrier Mix.