In need of support

I typically only post on here about topics related to movies and TV shows, and to showcase my fanart. However, I could use some support from my fellow moviechatters. A few weeks ago I had to put my cat down. She'd been diagnosed with chronic kidney disease, which is common in older cats and incurable. Basically her kidneys were no longer filtering out toxins, so the toxins were building up in her system. I was given medication to help flush out the toxins, as well as fluids to inject into her to keep her hydrated. I did this for a few months, but eventually it got to the point where she wasn't responding to them. She kept getting sicker and sicker. I was told by her vet that because she was so old (in her 80's in cat years), the disease would only be manageable for a while, and that as time went on more of her body would start to shut down.

This has been one of the hardest things I've ever had to do. I've had that cat for thirteen years, after getting her as an adult in horrible living conditions. She was a constant in my life. Regardless of what I was going through, I still had her and I took comfort in that. And she brought me so much joy--more than I can describe. I know I did the right thing in letting her go and letting her rest, but it hurts immensely. I'm so used to her being around. Every day after work she'd greet me when I came into the house; now she's not there. Every evening when I sat down on my couch, she'd hop on my lap; now she doesn't come. I'm managing okay, but the days can feel so hollow now.

Some comforting words would be much appreciated. Thank you all in advance.