I'm so sorry for your loss. We had a wonderful cat that we swear acted more like a dog than a cat. She got breast cancer of all things and we had to make a the tough decision to put her to sleep when it was obvious she was in too much pain. Our vet sent us a poem called "The Rainbow Bridge". It's a wonderful poem that you can google. We didn't wait very long before we added two more cats to our home, then a dog, and then two more cats just recently. I have two of the cats in my chair with me right now. They add so much joy to our lives but it hurts so much when you have to let them go. It's sweet that your other cat is spending more time with you. I think animals can sense when people are sad or sick.