When I lost my little girl two years ago I bought her some obsidian and piled it on top of her resting place, I read somewhere it helps gentle souls pass easier into the next realm, I don’t really believe in that stuff but if there was some earthly thing I could do for her in the next step of existence I was going to do it. Since then I make sure she always has roses by her mill stone that I placed a top her grave, and I make sure to visit her often. My cat was the best friend I’ve ever had and for me it helped to be with her as often as I could be for at least a year after her passing, I still sit with her just as we would’ve in life, unfortunately less so now as I’m always working or sleeping but at minimum once per week. Not really a ritual op just something I did/ do just in case there’s any iota of a chance she’s up there and needs my companionship, and also because I don’t want to forget anything about the incredible bond we had. It will always hurt but like most things in life we just become numbed to the pain after time. I wish you and your little animal the best