I'm so sorry, it's hard enough to lose a loved one but lose them like that is beyond tragic.
I had a cocker spaniel who was my first dog who belonged to me alone. I had to put him down because of medical complications and I was devestated. Shortly after I brought Jazzy home and it took me several months to truly bond to her. I liked her and took care of her, but I did not love and bond to her for at least 3-4 months.
It does get better and you do learn to appreciate the new dog for who they are.
Jasmine - Female Miniature Poodle - born Aug 15, 2010
Loker Delgado Von Stalworth - Male GSD - born Jan 26, 2012
Koda & Zazu - 5 year old male cats
Alex - Male Cocker Spaniel (rescue) - RIP Cuddlebug 2007-2010