I need some help! I grew up with all strays, adopted cats and dogs and they all got along. I rescued a stray, Bella, who passed away after 18 years. I also rescued a cat 5 years later, Callie, and the two were best friends. After Bella passed Callie seemed depressed. I decided to adopt a stray, Lyla, last June 2022. I slowly introduced them, but I noticed my new cat Lyla, seemed to be aggressive with Callie, pinning her to the ground and biting her in the neck. My vet and shelter told me not to separate them and eventually they will get along. I am home 24 hours and do playtime 3'xs a day and have every interactive cat toy. This has not helped Lyla's aggression with Calie. I feel like she is jealous of Callie to the point when Callie comes to me Lyla attacks her and chases her. Callie can't eat or play without Lyla jumping on her biting her neck. I love them both, but I am really feeling sorry for Callie because she has no life anymore with Lula around. Yes, they are both spayed. It was suggested that Lyla needs a one cat home, and it isn't fair to Callie. Lyla is physically abusive to Callie pinning her down and biting her neck. Lyla is asleep on my lap and Callie is upstairs. I bought a large cat tree, so Callie had a place to jump on to get away and this worked until Lyla decided this top perch was hers, so she won't let Callie near the cat tree. I feel bad for Lyla because she must have abandonment issues and I feel bad for Callie being bullied. i would never give Lyla up I am committed that she has a forever home. I am lost and need help please.